134-403: The Conowingo Dam (also Conowingo Hydroelectric Plant , Conowingo Hydroelectric Station ) is a large hydroelectric dam in the lower Susquehanna River near the town of Conowingo , Maryland . The medium-height, masonry gravity dam is one of the largest non-federal hydroelectric dams in the U.S., and the largest dam in the state of Maryland. The dam sits about 9.9 miles (16 km) from
268-745: A greenhouse gas . According to the World Commission on Dams report, where the reservoir is large compared to the generating capacity (less than 100 watts per square metre of surface area) and no clearing of the forests in the area was undertaken prior to impoundment of the reservoir, greenhouse gas emissions from the reservoir may be higher than those of a conventional oil-fired thermal generation plant. In boreal reservoirs of Canada and Northern Europe, however, greenhouse gas emissions are typically only 2% to 8% of any kind of conventional fossil-fuel thermal generation. A new class of underwater logging operation that targets drowned forests can mitigate
402-463: A low-head hydro power plant with hydrostatic head of few meters to few tens of meters can be classified either as an SHP or an LHP. The other distinction between SHP and LHP is the degree of the water flow regulation: a typical SHP primarily uses the natural water discharge with very little regulation in comparison to an LHP. Therefore, the term SHP is frequently used as a synonym for the run-of-the-river power plant . The largest power producers in
536-743: A 24-hour particle pollution rating of D in the American Lung Association 's 2017 State of the Air report, which analyzed data from 2013 to 2015. The city was ranked 22nd for ozone, 20th for short-term particle pollution, and 11th for year-round particle pollution. According to the same report, the city experienced a significant reduction in high ozone days since 2001—from nearly 50 days per year to fewer than 10—along with fewer days of high particle pollution since 2000—from about 19 days per year to about 3—and an approximate 30% reduction in annual levels of particle pollution since 2000. Five of
670-495: A bachelor's degree or higher. 23.9% spoke a language other than English at home, the most common of which was Spanish (10.8%). 15.0% of the populations foreign born, roughly half of whom are naturalized U.S. citizens. 3.7% of the population are veterans. The median household income was $ 52,889 and 22.8% of the population lived in poverty. 49.5% of the population drove alone to work, while 23.2% used public transit, 8.2% carpooled, 7.9% walked, and 7.0% worked from home. The average commute
804-403: A budget of $ 371 million. The Philadelphia Parking Authority is responsible for ensuring adequate parking for city residents, businesses, and visitors. Philadelphia's architectural history dates back to colonial times and includes a wide range of styles. The earliest structures were constructed with logs , but brick structures were common by 1700. During the 18th century, the cityscape
938-474: A city on the Delaware River to serve as a port and place for government. Hoping that Philadelphia would become more like an English rural town instead of a city, Penn laid out roads on a grid plan to keep houses and businesses spread far apart with areas for gardens and orchards . The city's inhabitants did not follow Penn's plans, however, and instead crowded the present-day Port of Philadelphia on
1072-496: A facility grid power failure. In 1936, all the floodgates were opened for the first time. During Hurricane Agnes , in June 1972, all 53 floodgates were opened, for only the second time, and explosives planted to blow a section of the weir , as the waters rose during the early morning hours of June 24 within 5 feet (1.52 m) of topping the dam (a record crest of 111.5 ft (34.0 m), 3 feet (0.91 m) above normal level for
1206-421: A flood and fail. Changes in the amount of river flow will correlate with the amount of energy produced by a dam. Lower river flows will reduce the amount of live storage in a reservoir therefore reducing the amount of water that can be used for hydroelectricity. The result of diminished river flow can be power shortages in areas that depend heavily on hydroelectric power. The risk of flow shortage may increase as
1340-497: A grid pattern between the Delaware and Schuylkill rivers that is aligned with their courses. The original city plan was designed to allow for easy travel and to keep residences separated by open space that would help prevent the spread of fire. In keeping with the idea of a "Greene Countrie Towne", and inspired by the many types of trees that grew in the region, Penn named many of the east–west streets for local trees. Penn planned
1474-716: A growth in its population in 2007, which continued with incremental annual increases through the present. A migration pattern has been established from New York City to Philadelphia by residents opting for a large city with relative proximity and a lower cost of living . Philadelphia's geographic center is about 40° 0′ 34″ north latitude and 75° 8′ 0″ west longitude. The 40th parallel north passes through neighborhoods in Northeast Philadelphia , North Philadelphia , and West Philadelphia including Fairmount Park . The city encompasses 142.71 square miles (369.62 km ), of which 134.18 square miles (347.52 km )
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#17327932099481608-494: A hydroelectric complex is constructed, it produces no direct waste, and almost always emits considerably less greenhouse gas than fossil fuel -powered energy plants. However, when constructed in lowland rainforest areas, where part of the forest is inundated, substantial amounts of greenhouse gases may be emitted. Construction of a hydroelectric complex can have significant environmental impact, principally in loss of arable land and population displacement. They also disrupt
1742-631: A joint effort between former mayors John F. Street and Michael Nutter . The zoning changes were intended to rectify incorrect zoning maps to facilitate future community development, as the city forecasts an additional 100,000 residents and 40,000 jobs will be added by 2035. The Philadelphia Housing Authority (PHA) is the largest landlord in Pennsylvania. Established in 1937, the PHA is the nation's fourth-largest housing authority, serving about 81,000 people with affordable housing, while employing 1,400 on
1876-809: A large natural height difference between two waterways, such as a waterfall or mountain lake. A tunnel is constructed to take water from the high reservoir to the generating hall built in a cavern near the lowest point of the water tunnel and a horizontal tailrace taking water away to the lower outlet waterway. A simple formula for approximating electric power production at a hydroelectric station is: P = − η ( m ˙ g Δ h ) = − η ( ( ρ V ˙ ) g Δ h ) {\displaystyle P=-\eta \ ({\dot {m}}g\ \Delta h)=-\eta \ ((\rho {\dot {V}})\ g\ \Delta h)} where Efficiency
2010-451: A larger amount of methane than those in temperate areas. Like other non-fossil fuel sources, hydropower also has no emissions of sulfur dioxide, nitrogen oxides, or other particulates. Reservoirs created by hydroelectric schemes often provide facilities for water sports , and become tourist attractions themselves. In some countries, aquaculture in reservoirs is common. Multi-use dams installed for irrigation support agriculture with
2144-563: A lesser extent the Holtwood and Safe Harbor Dams farther upstream, stopped migratory fish species, especially American shad , from swimming further up the Susquehanna River to spawn. In 1984, a fish capture feature was added at Conowingo and shad were trucked upstream above all three dams and released. This program ended in 1999. A fish lift was installed in 1991. All three dams completed installation of fish lifts in time for
2278-559: A moderately sunny climate with an average of 2,498 hours of sunshine annually. The percentage of sunshine ranges from 47% in December to 61% in June, July, and August. The January daily average temperature is 33.7 °F (0.9 °C). The temperature frequently rises to 50 °F (10 °C) during thaws. July averages 78.7 °F (25.9 °C). Heat waves accompanied by high humidity and heat indices are frequent, with highs reaching or exceeding 90 °F (32 °C) on 30 days of
2412-592: A positive risk adjusted return, unless appropriate risk management measures are put in place. While many hydroelectric projects supply public electricity networks, some are created to serve specific industrial enterprises. Dedicated hydroelectric projects are often built to provide the substantial amounts of electricity needed for aluminium electrolytic plants, for example. The Grand Coulee Dam switched to support Alcoa aluminium in Bellingham, Washington , United States for American World War II airplanes before it
2546-540: A primary black start power source if the regional PJM power grid ever had a widespread emergency shutdown ( blackout ). The dam has 53 flood control gates , starting at the northeastern end of the powerhouse and spanning the majority of the dam. The floodgates are operated by three overhead cranes rated for 60 short tons (53.6 long tons; 54.4 t) each which were originally built by the Morgan Engineering Company of Ohio. The cranes run on rails
2680-548: A relatively constant water supply. Large hydro dams can control floods, which would otherwise affect people living downstream of the project. Managing dams which are also used for other purposes, such as irrigation , is complicated. In 2021 the IEA called for "robust sustainability standards for all hydropower development with streamlined rules and regulations". Large reservoirs associated with traditional hydroelectric power stations result in submersion of extensive areas upstream of
2814-540: A result of climate change . One study from the Colorado River in the United States suggest that modest climate changes, such as an increase in temperature in 2 degree Celsius resulting in a 10% decline in precipitation, might reduce river run-off by up to 40%. Brazil in particular is vulnerable due to its heavy reliance on hydroelectricity, as increasing temperatures, lower water flow and alterations in
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#17327932099482948-448: A small TV/radio). Even smaller turbines of 200–300 W may power a few homes in a developing country with a drop of only 1 m (3 ft). A Pico-hydro setup is typically run-of-the-river , meaning that dams are not used, but rather pipes divert some of the flow, drop this down a gradient, and through the turbine before returning it to the stream. An underground power station is generally used at large facilities and makes use of
3082-455: A source of low-cost renewable energy. Alternatively, small hydro projects may be built in isolated areas that would be uneconomic to serve from a grid, or in areas where there is no national electrical distribution network. Since small hydro projects usually have minimal reservoirs and civil construction work, they are seen as having a relatively low environmental impact compared to large hydro. This decreased environmental impact depends strongly on
3216-414: A start-up time of the order of a few minutes. Although battery power is quicker its capacity is tiny compared to hydro. It takes less than 10 minutes to bring most hydro units from cold start-up to full load; this is quicker than nuclear and almost all fossil fuel power. Power generation can also be decreased quickly when there is a surplus power generation. Hence the limited capacity of hydropower units
3350-815: A time, row houses built elsewhere in the United States were known as "Philadelphia rows". A variety of row houses are found throughout the city, from Federal-style continuous blocks in Old City and Society Hill to Victorian-style homes in North Philadelphia to twin row houses in West Philadelphia . While newer homes have been built recently, much of the housing dates to the 18th, 19th, and early 20th centuries, which has created problems such as urban decay and vacant lots. Some neighborhoods, including Northern Liberties and Society Hill, have been rehabilitated through gentrification . As of 2014 ,
3484-581: A total of 1,500 terawatt-hours (TWh) of electrical energy in one full cycle" which was "about 170 times more energy than the global fleet of pumped storage hydropower plants". Battery storage capacity is not expected to overtake pumped storage during the 2020s. When used as peak power to meet demand, hydroelectricity has a higher value than baseload power and a much higher value compared to intermittent energy sources such as wind and solar. Hydroelectric stations have long economic lives, with some plants still in service after 50–100 years. Operating labor cost
3618-657: A town in Finland with a Swedish majority. In 1655, a Dutch military campaign led by New Netherland Director-General Peter Stuyvesant took control of the Swedish colony, ending its claim to independence. The Swedish and Finnish people settlers continued to have their own militia , religion, and court, and to enjoy substantial autonomy under the Dutch. An English fleet captured the New Netherland colony in 1664, though
3752-499: A year's worth of rain fell within 24 hours (see 1975 Banqiao Dam failure ). The resulting flood resulted in the deaths of 26,000 people, and another 145,000 from epidemics. Millions were left homeless. The creation of a dam in a geologically inappropriate location may cause disasters such as 1963 disaster at Vajont Dam in Italy, where almost 2,000 people died. Philadelphia Philadelphia , colloquially referred to as Philly ,
3886-452: Is hydroelectric power on a scale serving a small community or industrial plant. The definition of a small hydro project varies but a generating capacity of up to 10 megawatts (MW) is generally accepted as the upper limit. This may be stretched to 25 MW and 30 MW in Canada and the United States. Small hydro stations may be connected to conventional electrical distribution networks as
4020-635: Is also usually low, as plants are automated and have few personnel on site during normal operation. Where a dam serves multiple purposes, a hydroelectric station may be added with relatively low construction cost, providing a useful revenue stream to offset the costs of dam operation. It has been calculated that the sale of electricity from the Three Gorges Dam will cover the construction costs after 5 to 8 years of full generation. However, some data shows that in most countries large hydropower dams will be too costly and take too long to build to deliver
4154-470: Is highest in the winter when solar energy is at a minimum. Pico hydro is hydroelectric power generation of under 5 kW . It is useful in small, remote communities that require only a small amount of electricity. For example, the 1.1 kW Intermediate Technology Development Group Pico Hydro Project in Kenya supplies 57 homes with very small electric loads (e.g., a couple of lights and a phone charger, or
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4288-466: Is highly variable. Some winters have only light snow while others include major snowstorms. The normal seasonal snowfall averages 22.4 in (57 cm), with rare snowfalls in November or April, and rarely any sustained snow cover. Seasonal snowfall accumulation has ranged from trace amounts in 1972–73, to 78.7 inches (200 cm) in the winter of 2009–10. The city's heaviest single-storm snowfall
4422-492: Is home to five Fortune 500 corporate headquarters. Metropolitan Philadelphia ranks as one of the Big Five U.S. venture capital hubs, facilitated by its geographic proximity to both the entrepreneurial and financial ecosystems of New York City and to the federal regulatory environment of Washington, D.C. Greater Philadelphia is also a biotechnology hub. The Philadelphia Stock Exchange , owned by Nasdaq since 2008,
4556-445: Is initially produced during construction of the project, and some methane is given off annually by reservoirs, hydro has one of the lowest lifecycle greenhouse gas emissions for electricity generation. The low greenhouse gas impact of hydroelectricity is found especially in temperate climates . Greater greenhouse gas emission impacts are found in the tropical regions because the reservoirs of power stations in tropical regions produce
4690-665: Is land and 8.53 square miles (22.09 km ), or 6%, is water. Natural bodies of water include the Delaware and Schuylkill rivers, lakes in Franklin Delano Roosevelt Park , and Cobbs , Wissahickon , and Pennypack creeks. The largest artificial body of water is East Park Reservoir in Fairmount Park . The lowest point is sea level and the highest point is in Chestnut Hill , about 446 feet (136 m) above sea level on Summit Street near
4824-462: Is not an energy source, and appears as a negative number in listings. Run-of-the-river hydroelectric stations are those with small or no reservoir capacity, so that only the water coming from upstream is available for generation at that moment, and any oversupply must pass unused. A constant supply of water from a lake or existing reservoir upstream is a significant advantage in choosing sites for run-of-the-river. A tidal power station makes use of
4958-452: Is not generally used to produce base power except for vacating the flood pool or meeting downstream needs. Instead, it can serve as backup for non-hydro generators. The major advantage of conventional hydroelectric dams with reservoirs is their ability to store water at low cost for dispatch later as high value clean electricity. In 2021, the IEA estimated that the "reservoirs of all existing conventional hydropower plants combined can store
5092-410: Is often higher (that is, closer to 1) with larger and more modern turbines. Annual electric energy production depends on the available water supply. In some installations, the water flow rate can vary by a factor of 10:1 over the course of a year. Hydropower is a flexible source of electricity since stations can be ramped up and down very quickly to adapt to changing energy demands. Hydro turbines have
5226-501: Is often ranked as the nation's best city for professional sports fans. The city has a culturally and philanthropically active LGBTQ+ community . Philadelphia also has played an immensely influential historic and ongoing role in the development and evolution of American music, especially R&B , soul , and rock . As of 2022 , the Philadelphia metropolitan area had a gross metropolitan product of US$ 518.5 billion and
5360-598: Is one of the largest contiguous urban park areas in the U.S. The two parks, along with the Colonial Revival , Georgian and Federal -style mansions in them, have been listed as one entity on the National Register of Historic Places since 1972. Within the Köppen climate classification , Philadelphia falls under the northern periphery of the humid subtropical climate zone (Köppen Cfa ). Within
5494-602: Is the most populous city in the U.S. state of Pennsylvania and the sixth-most populous city in the United States , with a population of 1,603,797 in the 2020 census . The city is the urban core of the larger Delaware Valley , also known as the Philadelphia metropolitan area, the nation's eighth-largest metropolitan area and seventh-largest combined statistical area with 6.245 million residents and 7.366 million residents, respectively. Philadelphia has played an extensive role in United States history . The city
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5628-433: Is the nation's oldest stock exchange and a global leader in options trading. 30th Street Station , the city's primary rail station, is the third-busiest Amtrak hub in the nation, and the city's multimodal transportation and logistics infrastructure also includes Philadelphia International Airport , a major transatlantic gateway and transcontinental hub; the rapidly-growing PhilaPort seaport ; and Interstate 95 ,
5762-596: Is used as a drinking water supply for Baltimore and the Chester Water Authority ; as cooling water for the Peach Bottom Nuclear Generating Station ; and for recreational boating and fishing. In low rainfall or drought conditions, balancing the desire to maintain the reservoir level with the water flow needs for the downstream ecology is one of the challenges faced by the dam operators. The Conowingo Dam, and to
5896-456: The 2020 U.S. Census , there were 1,603,797 people residing in Philadelphia, representing a 1.2% increase from the 2019 census estimate. The racial composition of the city was 39.3% Black alone (42.0% Black alone or in combination), 36.3% White alone (41.9% White alone or in combination), 8.7% Asian alone, 0.4% American Indian and Alaska Native alone, 8.7% some other race, and 6.9% multiracial. 14.9% of residents were Hispanic or Latino. 34.8% had
6030-848: The Battle of Brandywine in Chadds Ford Township , on September 11, 1777, during the Philadelphia campaign , the revolutionary capital of Philadelphia was defenseless and the city prepared for what was perceived to be an inevitable British attack. Because bells could easily be recast into munitions, the Liberty Bell , then known as the Pennsylvania State Bell, and bells from two Philadelphia churches, Christ Church and St. Peter's Church , were hastily taken down and transported by heavily guarded wagon train out of
6164-679: The Bonneville Dam in 1937 and being recognized by the Flood Control Act of 1936 as the premier federal flood control agency. Hydroelectric power stations continued to become larger throughout the 20th century. Hydropower was referred to as "white coal". Hoover Dam 's initial 1,345 MW power station was the world's largest hydroelectric power station in 1936; it was eclipsed by the 6,809 MW Grand Coulee Dam in 1942. The Itaipu Dam opened in 1984 in South America as
6298-624: The British Army , which was then the world's most powerful military force. Since the Declaration's July 4, 1776, adoption, its signing has been cited globally and repeatedly by various peoples of the world seeking independence and liberty. It also has been, since its adoption, the basis for annual celebration by Americans; in 1938, this celebration of the Declaration was formalized as Independence Day , one of only eleven designated U.S. federal holidays . After George Washington 's defeat at
6432-614: The Delaware River watershed , western Long Island , and the Lower Hudson Valley . Most Lenape were pushed out of the region during the 18th century by expanding European colonies, exacerbated by losses from intertribal conflicts. Lenape communities were weakened by newly introduced diseases, mainly smallpox , and conflict with Europeans. The Iroquois occasionally fought the Lenape. Surviving Lenape moved west into
6566-684: The Eastern Mediterranean during the Greek and Roman periods, including modern Alaşehir , mentioned as the site of an early Christian congregation in the Book of Revelation . As a Quaker , Penn had experienced religious persecution and wanted his colony to be a place where anyone could worship freely. This tolerance, which exceeded that of other colonies, led to better relations with the local native tribes and fostered Philadelphia's rapid growth into America's most important city. Penn planned
6700-583: The Great Migration from the South . By the 20th century, Philadelphia had an entrenched Republican political machine and a complacent population. In 1910, a general strike shut down the entire city. In 1917, following outrage over the election-year murder of a Philadelphia police officer, led to the shrinking of the City Council from two houses to just one. In July 1919, Philadelphia
6834-806: The International Exhibition of Hydropower and Tourism , with over one million visitors 1925. By 1920, when 40% of the power produced in the United States was hydroelectric, the Federal Power Act was enacted into law. The Act created the Federal Power Commission to regulate hydroelectric power stations on federal land and water. As the power stations became larger, their associated dams developed additional purposes, including flood control , irrigation and navigation . Federal funding became necessary for large-scale development, and federally owned corporations, such as
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#17327932099486968-615: The Liberty Bell , and hosting the Second Continental Congress during which the nation's 56 founders formed the Continental Army and elected George Washington as its commander in 1775, and unanimously adopted the Declaration of Independence on July 4, 1776. For nine months, from September 1777 to June 1778, the city fell under British occupation during the war's Philadelphia campaign . In 1787,
7102-608: The Occupational Safety and Health Act , which guaranteed the right to a safe job. While these men struggled to earn a living, many suffered disabling injuries handling high voltage electric lines, tumbling from high elevations, managing explosives, encountering venomous snakes, etc. When Maryland Public Television aired its documentary, "Conowingo Dam: Power on the Susquehanna" for Chesapeake Bay Week in April 2016,
7236-484: The Philadelphia area. The dam contributed 2.1 million megawatt-hours to the electrical grid in 2021. Through subsidiaries and mergers, the dam is now operated by the Susquehanna Electric Company, which is part of Constellation Energy . The current Federal Energy Regulatory Commission license for the dam was issued in 2021 and expires in 2071. The Conowingo Hydroelectric Station would be
7370-559: The Second Continental Congress , which adopted the Declaration of Independence in what was then called the Pennsylvania State House and was later renamed Independence Hall. Historian Joseph Ellis , in 2007, described the Declaration of Independence, written predominantly by Thomas Jefferson , as "the most potent and consequential words in American history," and its adoption represented a declaration of war against
7504-633: The Tennessee Valley Authority (1933) and the Bonneville Power Administration (1937) were created. Additionally, the Bureau of Reclamation which had begun a series of western US irrigation projects in the early 20th century, was now constructing large hydroelectric projects such as the 1928 Hoover Dam . The United States Army Corps of Engineers was also involved in hydroelectric development, completing
7638-480: The Trewartha climate classification , Philadelphia has a temperate maritime climate ( Do ) limited to the north by the continental climate ( Dc ). Summers are typically hot and muggy. Fall and spring are generally mild, and winter is moderately cold. The plant life hardiness zones are 7a and 7b, reflecting an average annual extreme minimum temperature between 0 and 10 °F (−18 and −12 °C). Snowfall
7772-669: The U.S. Constitution was ratified in Philadelphia at the Philadelphia Convention . Philadelphia remained the nation's largest city until 1790, and it served as the nation's first capital from May 10, 1775, until December 12, 1776, and on four subsequent occasions until 1800, when construction of the new national capital in Washington, D.C. was completed. Philadelphia maintains extensive contemporary influence in business and industry , culture , sports , and music . With 17 four-year universities and colleges in
7906-583: The Vulcan Street Plant , began operating September 30, 1882, in Appleton, Wisconsin , with an output of about 12.5 kilowatts. By 1886 there were 45 hydroelectric power stations in the United States and Canada; and by 1889 there were 200 in the United States alone. At the beginning of the 20th century, many small hydroelectric power stations were being constructed by commercial companies in mountains near metropolitan areas. Grenoble , France held
8040-506: The potential energy of dammed water driving a water turbine and generator . The power extracted from the water depends on the volume and on the difference in height between the source and the water's outflow. This height difference is called the head . A large pipe (the " penstock ") delivers water from the reservoir to the turbine. This method produces electricity to supply high peak demands by moving water between reservoirs at different elevations. At times of low electrical demand,
8174-528: The river mouth at the Chesapeake Bay , 5 miles (8 km) south of the Pennsylvania border and 45 miles (72 km) northeast of Baltimore , on the border between Cecil and Harford counties. The dam supports a 9,000-acre reservoir, which today covers the original town of Conowingo. During dam construction, the town was moved to its present location about 1 mile (1.6 km) northeast of
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#17327932099488308-448: The world's 54th-largest urban park . Philadelphia is known for its arts, culture , cuisine , and colonial and Revolutionary-era history; in 2016, it attracted 42 million domestic tourists who spent $ 6.8 billion, representing $ 11 billion in economic impact to the city and its surrounding Pennsylvania counties. With five professional sports teams and one of the nation's most loyal and passionate fan bases, Philadelphia
8442-490: The 1980s. Historic areas such as Old City and Society Hill were renovated during the reformist mayoral era of the 1950s through the 1980s, making both areas among the most desirable Center City neighborhoods. Immigrants from around the world began to enter the U.S. through Philadelphia as their gateway, leading to a reversal of the city's population decline between 1950 and 2000, during which it lost about 25 percent of its residents. Philadelphia eventually began experiencing
8576-665: The 2 square miles (5.2 km ) of Center City to the roughly 134 square miles (350 km ) of Philadelphia County . In the latter half of the 19th century and leading into the 20th century, immigrants from Russia, Eastern Europe, and Italy, and African Americans from the southern U.S. settled in the city. Philadelphia was represented by the Washington Grays in the American Civil War . The African-American population of Philadelphia increased from 31,699 to 219,559 between 1880 and 1930, largely stemming from
8710-512: The 2000 season. During the 2000 migration season, 153,000 American shad passed through the Conowingo fish lift. "However, passage rates of shad from Conowingo to Holtwood have been only 30 to 50 percent, suggesting that fish are having difficulty moving upstream in the waters of the Conowingo pool." The three dams are also involved with another ecological concern. Normally, the reservoirs above each dam trap sediment and nutrients that run off from
8844-543: The 53 floodgates were opened due to rising floodwaters resulting from several days of torrential downpours in the Mid-Atlantic . The Susquehanna River saw water levels of over 26.25 feet (8.00 m), placing nearby cities, like Port Deposit, at risk of flooding like in 2011. The ecological impact of this event is not known, but Chesapeake Bay ecologists are concerned about the health of the Chesapeake Bay with
8978-511: The Delaware River and subdivided and resold their lots. Before Penn left Philadelphia for the final time, he issued the Charter of 1701 establishing it as a city. Though poor at first, Philadelphia became an important trading center with tolerable living conditions by the 1750s. Benjamin Franklin , a leading citizen, helped improve city services and founded new ones that were among the first in
9112-463: The IEA released a main-case forecast of 141 GW generated by hydropower over 2022–2027, which is slightly lower than deployment achieved from 2017–2022. Because environmental permitting and construction times are long, they estimate hydropower potential will remain limited, with only an additional 40 GW deemed possible in the accelerated case. In 2021 the IEA said that major modernisation refurbishments are required. Most hydroelectric power comes from
9246-794: The Second Continental Congress adopted the Articles of Confederation on November 15, 1777, and the city later served as the meeting place for the Constitutional Convention , which ratified the Constitution in Independence Hall in Philadelphia on September 17, 1787. Philadelphia served as capital of the United States for much of the colonial and early post-colonial periods, including for a decade, from 1790 to 1800, while Washington, D.C. ,
9380-469: The Susquehanna River watershed and prevent some of that from reaching the Chesapeake Bay. A 1998 USGS study suggests that the reservoirs may reach capacity before 2020, and cease to reduce the nutrient and sediment load hitting the bay. However, the scouring of major floods, and other factors, affect this. Hydroelectric Hydroelectricity , or hydroelectric power , is electricity generated from hydropower (water power). Hydropower supplies 15% of
9514-585: The United States after Midtown Manhattan in New York City. Philadelphia's neighborhoods are divided into six large sections that surround Center City: North Philadelphia , Northeast Philadelphia , South Philadelphia , Southwest Philadelphia , West Philadelphia , and Northwest Philadelphia . The city's geographic boundaries have been largely unchanged since these neighborhoods were consolidated in 1854. However, each of these large areas contains numerous neighborhoods, some of whose boundaries derive from
9648-420: The United States after Niagara Falls . Some 5,000 workers flocked to this rural northeastern corner of Maryland, seeking to earn good pay as construction got underway. In addition to those working directly on the dam, large numbers relocated railroad tracks, paved new roads, and constructed steel towers to stretch the heavy transmission lines toward Philadelphia. This was nearly fifty years before Congress passed
9782-464: The ability to transport particles heavier than itself downstream. This has a negative effect on dams and subsequently their power stations, particularly those on rivers or within catchment areas with high siltation. Siltation can fill a reservoir and reduce its capacity to control floods along with causing additional horizontal pressure on the upstream portion of the dam. Eventually, some reservoirs can become full of sediment and useless or over-top during
9916-595: The balance between stream flow and power production. Micro hydro means hydroelectric power installations that typically produce up to 100 kW of power. These installations can provide power to an isolated home or small community, or are sometimes connected to electric power networks. There are many of these installations around the world, particularly in developing nations as they can provide an economical source of energy without purchase of fuel. Micro hydro systems complement photovoltaic solar energy systems because in many areas water flow, and thus available hydro power,
10050-472: The boroughs, townships, and other communities that constituted Pennsylvania County before their inclusion within the city. The City Planning Commission , tasked with guiding growth and development of the city, has divided the city into 18 planning districts as part of the Philadelphia2035 physical development plan. Much of the city's 1980 zoning code was overhauled from 2007 to 2012 as part of
10184-587: The city for its outlying railroad commuting towns and newer housing. The resulting reduction in Philadelphia's tax base and the resources of local government caused the city to struggle through a long period of adjustment, and it approached bankruptcy by the late 1980s. In 1985, the MOVE Bombing of the Cobbs Creek neighborhood by city helicopters occurred, killing 11 and destroying 61 homes. Revitalization and gentrification of neighborhoods began in
10318-532: The city's 17th century founding through the present, Philadelphia has been the birthplace or home to an extensive number of prominent and influential Americans . Prior to the arrival of Europeans in the early 17th century, the Philadelphia area was home to the Lenape Indians in the village of Shackamaxon . They were also called the Delaware Indians, and their historical territory was along
10452-456: The city's director of public safety, but political pressure still prevented long-term success in fighting crime and corruption. In 1940, non-Hispanic whites constituted 86.8% of the city's population. In 1950, the population peaked at more than two million residents, then began to decline with the restructuring of industry that led to the loss of many middle-class union jobs. In addition, suburbanization enticed many affluent residents to depart
10586-399: The city's tallest building. The Comcast Technology Center was completed in 2018, reaching a height of 1,121 ft (342 m), as the tallest building in the United States outside of Manhattan and Chicago. For much of Philadelphia's history, the typical home has been the row house . The row house was introduced to the United States via Philadelphia in the early 19th century and, for
10720-519: The city's total park space, including municipal, state, and federal parks in the city, amounts to 11,211 acres (17.5 sq mi). Philadelphia's largest park is Fairmount Park , which includes the Philadelphia Zoo and encompasses 2,052 acres (3.2 sq mi) of the total parkland. Fairmount Park's adjacent Wissahickon Valley Park contains 2,042 acres (3.2 sq mi). Fairmount Park, when combined with Wissahickon Valley Park,
10854-403: The city, Philadelphia is one of the nation's leading centers for higher education and academic research . The city is a national cultural center, hosting more outdoor sculptures and murals than any other city in the nation. Fairmount Park , when combined with adjacent Wissahickon Valley Park in the same watershed , is 2,052 acres (830 ha), representing one of the nation's largest and
10988-694: The city. The Liberty Bell was taken to Zion German Reformed Church in Northampton Town, which is present-day Allentown , where it was hidden under the church's floor boards for nine months from September 1777 until the British Army's departure from Philadelphia in June 1778. Two Revolutionary War battles, the Siege of Fort Mifflin , fought between September 26 and November 16, 1777, and the Battle of Germantown , fought on October 4, 1777, took place within Philadelphia's city limits. In Philadelphia,
11122-608: The colonies made it a natural center for America's revolutionaries . By the 1750s, Philadelphia surpassed Boston as the largest city and busiest port in British America , and the second-largest city in the entire British Empire after London . In 1774, as resentment of British colonial practices and support for independence was burgeoning in the colonies, Philadelphia hosted the First Continental Congress . From 1775 to 1781, Philadelphia hosted
11256-473: The colony. Penn made a treaty of friendship with Lenape chief Tammany under an elm tree at Shackamaxon , in what is now the city's Fishtown neighborhood. Penn named the city Philadelphia, which is Greek for "brotherly love", derived from the Ancient Greek terms φίλος phílos (beloved, dear) and ἀδελφός adelphós (brother, brotherly). There were a number of cities named Philadelphia in
11390-493: The construction contract for the dam to Stone & Webster of Boston , who did the design. Construction, which started in 1926, was carried out by the Arundel Corporation of Maryland. (Abandoned railroad tracks for transporting heavy equipment to the dam site can be seen along the western shore of the river below the dam.) When completed in 1928, it was the second-largest hydroelectric project by power output in
11524-402: The country, and the first Black Episcopal Church . The free Black community also established many schools for its children with the help of Quakers . Large-scale construction projects for new roads, canals , and railroads made Philadelphia the first major industrial city in the United States. Throughout the 19th century, Philadelphia hosted a variety of industries and businesses; the largest
11658-490: The creation of five public parks in the city which were renamed in 1824. Centre Square was renamed Penn Square ; Northeast Square was renamed Franklin Square ; Southeast Square was renamed Washington Square ; Southwest Square was renamed Rittenhouse Square ; and Northwest Square was renamed Logan Circle/Square . Center City had an estimated 183,240 residents as of 2015 , making it the second-most populated downtown area in
11792-404: The daily rise and fall of ocean water due to tides; such sources are highly predictable, and if conditions permit construction of reservoirs, can also be dispatchable to generate power during high demand periods. Less common types of hydro schemes use water's kinetic energy or undammed sources such as undershot water wheels . Tidal power is viable in a relatively small number of locations around
11926-471: The dam's eastern end. The rising water also would have covered Conowingo Bridge , the original U.S. Route 1 crossing, so it was demolished in 1927. U.S. Route 1 now crosses over the top of the dam. The Conowingo Reservoir , and the nearby Susquehanna State Park , provide many recreational opportunities. The area, which appears on a 1612 map by John Smith , was originally known as Smyth's Falls. On January 23, 1925, Philadelphia Electric Company awarded
12060-505: The dams, sometimes destroying biologically rich and productive lowland and riverine valley forests, marshland and grasslands. Damming interrupts the flow of rivers and can harm local ecosystems, and building large dams and reservoirs often involves displacing people and wildlife. The loss of land is often exacerbated by habitat fragmentation of surrounding areas caused by the reservoir. Hydroelectric projects can be disruptive to surrounding aquatic ecosystems both upstream and downstream of
12194-405: The eastern shore). In 1978, four higher-capacity turbines were added. Each of these turbines drives a 65-megawatt generator, increasing the dam's electrical output capacity from 252 to 548 megawatts. The four newer turbines are in the open air section at the northeast end of the powerhouse. The generators produce power at 13,800 volts. This is stepped up to 220,000 volts for transmission, primarily to
12328-705: The effect of forest decay. Another disadvantage of hydroelectric dams is the need to relocate the people living where the reservoirs are planned. In 2000, the World Commission on Dams estimated that dams had physically displaced 40–80 million people worldwide. Because large conventional dammed-hydro facilities hold back large volumes of water, a failure due to poor construction, natural disasters or sabotage can be catastrophic to downriver settlements and infrastructure. During Typhoon Nina in 1975 Banqiao Dam in Southern China failed when more than
12462-440: The entire 14-mile (23 km) long Conowingo Reservoir.) Paul English, dam superintendent, released a bulletin at 10:30 p.m. on June 23 saying that the water levels were reaching a point at which the stability of the dam "cannot be controlled. When it reaches 111 feet (33.8 m)...it will be in the hazy area...It is not known...whether a structure of the dam may give and...people downstream should be advised." At this time,
12596-399: The excess generation capacity is used to pump water into the higher reservoir, thus providing demand side response . When the demand becomes greater, water is released back into the lower reservoir through a turbine. In 2021 pumped-storage schemes provided almost 85% of the world's 190 GW of grid energy storage and improve the daily capacity factor of the generation system. Pumped storage
12730-620: The first modern International Style skyscraper in the United States, the PSFS Building , designed by George Howe and William Lescaze . The 548 ft (167 m) City Hall remained the tallest building in the city until 1987 when One Liberty Place was completed. Numerous glass and granite skyscrapers were built in Center City beginning in the late 1980s. In 2007, the Comcast Center surpassed One Liberty Place to become
12864-543: The first official World's fair in the U.S. Immigrants, mostly from Ireland and Germany, settled in Philadelphia and the surrounding districts. These immigrants were largely responsible for the first general strike in North America in 1835, in which workers in the city won the ten-hour workday. The city was a destination for thousands of Irish immigrants fleeing the Great Famine in the 1840s; housing for them
12998-419: The flow sensor in the dam recorded its record discharge of 1,130,000 cu ft/s (32,000 m/s), and the stream height gauge, at the dam's downstream side, registered a record 36.85 feet (11.23 m). On January 20, 1996, the gauge recorded its second-highest recorded crest of 34.18 feet (10.42 m). A severe ice jam also developed behind the dam on this date. The record minimum recorded discharge
13132-456: The influx of sediment and limiting nutrients, such as phosphorus and nitrogen, impacting water clarity and promoting algal blooms . The Coast Guard issued warnings for all vessels in the Chesapeake Bay regarding the fields of debris, floating and submerged, that had been released when the floodgates opened. The river water impounded by the dam forms the 14-mile (23 km) long Conowingo Reservoir, known locally as Conowingo Lake. The reservoir
13266-627: The intersection of Germantown Avenue and Bethlehem Pike at: 40.07815 N, 75.20747 W. Philadelphia is located on the Atlantic Seaboard Fall Line that separates the Atlantic Plain from the Piedmont . The Schuylkill River's rapids at East Falls were inundated by completion of the dam at Fairmount Water Works . The city is the seat of its own county . The city is bordered by six adjacent counties: Montgomery to
13400-501: The largest amount for the region since 1990. Meanwhile, globally, hydropower generation increased by 70 TWh (up 2%) in 2022 and remains the largest renewable energy source, surpassing all other technologies combined. Hydropower has been used since ancient times to grind flour and perform other tasks. In the late 18th century hydraulic power provided the energy source needed for the start of the Industrial Revolution . In
13534-750: The largest, producing 14 GW , but was surpassed in 2008 by the Three Gorges Dam in China at 22.5 GW . Hydroelectricity would eventually supply some countries, including Norway , Democratic Republic of the Congo , Paraguay and Brazil , with over 85% of their electricity. In 2021 the International Energy Agency (IEA) said that more efforts are needed to help limit climate change . Some countries have highly developed their hydropower potential and have very little room for growth: Switzerland produces 88% of its potential and Mexico 80%. In 2022,
13668-551: The last occurrence of such a temperature being July 21, 2019. The lowest officially recorded temperature was −11 °F (−24 °C) on February 9, 1934. Temperatures at or below 0 °F (−18 °C) are rare, with the last such occurrence being January 19, 1994 . The record low maximum is 5 °F (−15 °C) on February 10, 1899, and December 30, 1880. The record high minimum is 83 °F (28 °C) on July 23, 2011, and July 24, 2010. See or edit raw graph data . Philadelphia County received an ozone grade of F and
13802-546: The late 1970s and continues into the 21st century with much of the development occurring in the Center City and University City neighborhoods. But this expanded a shortage of affordable housing in the city. After many manufacturers and businesses left Philadelphia or shut down, the city started attracting service businesses and began to market itself more aggressively as a tourist destination. Contemporary glass-and-granite skyscrapers were built in Center City beginning in
13936-616: The late 19th century, the electrical generator was developed and could now be coupled with hydraulics. The growing demand arising from the Industrial Revolution would drive development as well. In 1878, the world's first hydroelectric power scheme was developed at Cragside in Northumberland , England, by William Armstrong . It was used to power a single arc lamp in his art gallery. The old Schoelkopf Power Station No. 1 , US, near Niagara Falls , began to produce electricity in 1881. The first Edison hydroelectric power station,
14070-435: The length of the dam and are electrically powered from lines that run above the face of the dam. A 4th crane was installed in 2006 at the powerhouse end of the rails, which required installing new power rails below the existing power wires. By 2017, all original overhead cranes had been replaced. The original Morgan cranes were removed and scrapped. The new cranes have backup generators installed on them to allow operation during
14204-488: The mid-1700s, French engineer Bernard Forest de Bélidor published Architecture Hydraulique , which described vertical- and horizontal-axis hydraulic machines, and in 1771 Richard Arkwright 's combination of water power , the water frame , and continuous production played a significant part in the development of the factory system, with modern employment practices. In the 1840s, hydraulic power networks were developed to generate and transmit hydro power to end users. By
14338-971: The nation, including a fire company , library , and hospital . A number of philosophical societies were formed, which were centers of the city's intellectual life, including the Philadelphia Society for Promoting Agriculture (1785), the Pennsylvania Society for the Encouragement of Manufactures and the Useful Arts (1787), the Academy of Natural Sciences (1812), and the Franklin Institute (1824). These societies developed and financed new industries that attracted skilled and knowledgeable immigrants from Europe. Philadelphia's importance and central location in
14472-651: The natural ecology of the river involved, affecting habitats and ecosystems, and siltation and erosion patterns. While dams can ameliorate the risks of flooding, dam failure can be catastrophic. In 2021, global installed hydropower electrical capacity reached almost 1,400 GW, the highest among all renewable energy technologies. Hydroelectricity plays a leading role in countries like Brazil, Norway and China. but there are geographical limits and environmental issues. Tidal power can be used in coastal regions. China added 24 GW in 2022, accounting for nearly three-quarters of global hydropower capacity additions. Europe added 2 GW,
14606-449: The northwest; Bucks to the north and northeast; Burlington County, New Jersey to the east; Camden County, New Jersey to the southeast; Gloucester County, New Jersey to the south; and Delaware County to the southwest. Philadelphia was created in the 17th century, following the plan by William Penn 's surveyor Thomas Holme . Center City is structured with long, straight streets running nearly due east–west and north–south, forming
14740-633: The plant site. Generation of hydroelectric power changes the downstream river environment. Water exiting a turbine usually contains very little suspended sediment, which can lead to scouring of river beds and loss of riverbanks. The turbines also will kill large portions of the fauna passing through, for instance 70% of the eel passing a turbine will perish immediately. Since turbine gates are often opened intermittently, rapid or even daily fluctuations in river flow are observed. Drought and seasonal changes in rainfall can severely limit hydropower. Water may also be lost by evaporation. When water flows it has
14874-527: The question came up about how many workers died performing their duties. While investigating the death of Hunter H. Bettis on November 26, 1927, Darlington Coroner Wiliam B. Selse commented in The Baltimore Sun that more than twenty men had lost their lives. In an attempt to create a registry or census of job-related fatalities, death certificates, newspaper accounts, and funeral home books were examined. Fourteen individuals were identified. The dam
15008-450: The rainfall regime, could reduce total energy production by 7% annually by the end of the century. Lower positive impacts are found in the tropical regions. In lowland rainforest areas, where inundation of a part of the forest is necessary, it has been noted that the reservoirs of power plants produce substantial amounts of methane . This is due to plant material in flooded areas decaying in an anaerobic environment and forming methane,
15142-768: The second half of the 19th century. His contemporaries included John McArthur Jr. , Addison Hutton , Wilson Eyre , the Wilson Brothers , and Horace Trumbauer . In 1871, construction began on the Second Empire -style Philadelphia City Hall . The Philadelphia Historical Commission was created in 1955 to preserve the cultural and architectural history of the city. The commission maintains the Philadelphia Register of Historic Places , adding historic buildings, structures, sites, objects and districts as it sees fit. In 1932, Philadelphia became home to
15276-552: The situation did not change substantially until 1682, when the area was included in William Penn 's charter for Pennsylvania. In 1681, in partial repayment of a debt, Charles II of England granted Penn a charter for what would become the Pennsylvania colony . Despite the royal charter, Penn bought the land from the local Lenape in an effort to establish good terms with the Native Americans and ensure peace for
15410-467: The spine of the north–south highway system along the U.S. East Coast . Philadelphia is a city of many firsts, including the nation's first library (1731), hospital (1751), medical school (1765), national capital (1774), university (by some accounts) (1779), central bank (1781), stock exchange (1790), zoo (1874), and business school (1881). Philadelphia contains 67 National Historic Landmarks , including Independence Hall . From
15544-493: The surrounding Delaware Valley in the early 17th century. The first settlements were founded by Dutch colonists , who built Fort Nassau on the Delaware River in 1623 in what is now Brooklawn, New Jersey . The Dutch considered the entire Delaware River valley to be part of their New Netherland colony. In 1638, Swedish settlers led by renegade Dutch established the colony of New Sweden at Fort Christina , located in present-day Wilmington, Delaware , and quickly spread out in
15678-522: The ten largest combined statistical areas (CSAs) were ranked higher for ozone: Los Angeles (1st), New York City (9th), Houston (12th), Dallas (13th), and San Jose, California (18th). Many smaller CSAs were also ranked higher for ozone, including Sacramento (8th), Las Vegas (10th), Denver (11th), El Paso (16th), and Salt Lake City (20th). Only two of those same ten CSAs, San Jose and Los Angeles, were ranked higher than Philadelphia for both year-round and short-term particle pollution. As of
15812-629: The upper Ohio River basin. Following the American Revolutionary War and subsequent formation of an independent United States, the Lenape began moving further west. In the 1860s, the United States government sent most remaining Lenape in the eastern United States to the Indian Territory in present-day Oklahoma and surrounding territories as part of the Indian removal policy. Europeans first entered Philadelphia and
15946-587: The valley. In 1644, New Sweden supported the Susquehannocks in their war against Maryland colonists. In 1648, the Dutch built Fort Beversreede on the west bank of the Delaware, south of the Schuylkill River near the present-day Eastwick section of Philadelphia, to reassert their dominion over the area. The Swedes responded by building Fort Nya Korsholm , or New Korsholm , named after
16080-524: The world are hydroelectric power stations, with some hydroelectric facilities capable of generating more than double the installed capacities of the current largest nuclear power stations . Although no official definition exists for the capacity range of large hydroelectric power stations, facilities from over a few hundred megawatts are generally considered large hydroelectric facilities. Currently, only seven facilities over 10 GW ( 10,000 MW ) are in operation worldwide, see table below. Small hydro
16214-533: The world's electricity , almost 4,210 TWh in 2023, which is more than all other renewable sources combined and also more than nuclear power . Hydropower can provide large amounts of low-carbon electricity on demand, making it a key element for creating secure and clean electricity supply systems. A hydroelectric power station that has a dam and reservoir is a flexible source, since the amount of electricity produced can be increased or decreased in seconds or minutes in response to varying electricity demand. Once
16348-539: The world. The classification of hydropower plants starts with two top-level categories: The classification of a plant as an SHP or LHP is primarily based on its nameplate capacity , the threshold varies by the country, but in any case a plant with the capacity of 50 MW or more is considered an LHP. As an example, for China, SHP power is below 25 MW, for India - below 15 MW, most of Europe - below 10 MW. The SHP and LHP categories are further subdivided into many subcategories that are not mutually exclusive. For example,
16482-491: The year. The average window for freezing temperatures is November 6 to April 2, allowing a growing season of 217 days. Early fall and late winter are generally dry, with February having the lowest average precipitation at 2.75 inches (70 mm). The dewpoint in the summer averages between 59.1 and 64.5 °F (15 and 18 °C). The highest recorded temperature was 106 °F (41 °C) on August 7, 1918. Temperatures at or above 100 °F (38 °C) are not common, with
16616-541: Was 30.7 in (78 cm), which occurred in January 1996. Precipitation is generally spread throughout the year, with eight to eleven wet days per month, at an average annual rate of 44.1 inches (1,120 mm), but historically ranging from 29.31 in (744 mm) in 1922 to 64.33 in (1,634 mm) in 2011. The most rain recorded in one day occurred on July 28, 2013, when 8.02 in (204 mm) fell at Philadelphia International Airport . Philadelphia has
16750-586: Was allowed to provide irrigation and power to citizens (in addition to aluminium power) after the war. In Suriname , the Brokopondo Reservoir was constructed to provide electricity for the Alcoa aluminium industry. New Zealand 's Manapouri Power Station was constructed to supply electricity to the aluminium smelter at Tiwai Point . Since hydroelectric dams do not use fuel, power generation does not produce carbon dioxide . While carbon dioxide
16884-472: Was being constructed and prepared to serve as the new national capital. In 1793, the largest yellow fever epidemic in U.S. history killed approximately 4,000 to 5,000 people in Philadelphia, or about ten percent of the city's population at the time. The capital of the United States was moved to Washington, D.C. in 1800 upon completion of the White House and U.S. Capitol buildings. The state capital
17018-514: Was built with 11 turbine sites, although only 7 turbines were initially installed, driving generators each rated for 36 megawatts. A turbine house, on the southwestern end of the dam, encloses these seven units. One additional "house" unit provides 25 Hz power for the dam's electric railroad system (identical to that used by the Pennsylvania Railroad , which had an electrified line [now under Norfolk Southern ownership] running on
17152-514: Was developed south of South Street and later occupied by succeeding immigrants. They established a network of Catholic churches and schools and dominated the Catholic clergy for decades. Anti- Irish , anti-Catholic nativist riots erupted in Philadelphia in 1844. The rise in population of the surrounding districts helped lead to the Act of Consolidation of 1854 , which extended the city limits from
17286-482: Was dominated by Georgian architecture , including Independence Hall and Christ Church . In the first decades of the 19th century, Federal and Greek Revival architecture were the dominant styles produced by Philadelphia architects such as Benjamin Latrobe , William Strickland , John Haviland , John Notman , Thomas Walter , and Samuel Sloan . Frank Furness is considered Philadelphia's greatest architect of
17420-627: Was founded in 1682 by William Penn , an English Quaker and advocate of religious freedom , and served as the capital of the Pennsylvania Colony during the British colonial era . The city went on to play a historic and vital role during the American Revolution and Revolutionary War , serving as the central meeting place for the nation's founding fathers , hosting the First Continental Congress in 1774, preserving
17554-529: Was moved from Philadelphia to Lancaster in 1799, then ultimately to Harrisburg in 1812. Philadelphia remained the nation's largest city until the late 18th century. It also was the nation's financial and cultural center until ultimately being eclipsed in total population by New York City in 1790. In 1816, the city's free Black community founded the African Methodist Episcopal Church , the first independent Black denomination in
17688-411: Was on March 2, 1969, when the flow sensor registered 144 cu ft/s (4.1 m/s). On September 9, 2011, 44 flood gates were opened due to the impact of the remnants of Tropical Storm Lee . The Susquehanna River level behind the dam was 32.41 feet (9.88 m), the third-highest in history. The town of Port Deposit , located 5 miles southeast of the dam, was evacuated. On July 26, 2018, 20 of
17822-406: Was one of more than 36 industrial cities nationally to suffer a race riot during Red Summer in post- World War I unrest as recent immigrants competed with Blacks for jobs. In the 1920s, the public flouting of Prohibition laws, organized crime , mob violence, and corrupt police involvement in illegal activities led to the appointment of Brig. Gen. Smedley Butler of the U.S. Marine Corps as
17956-641: Was the textile industry . Major corporations in the 19th and early 20th centuries included the Baldwin Locomotive Works , William Cramp & Sons Shipbuilding Company , and the Pennsylvania Railroad . Established in 1870, the Philadelphia Conveyancers' Association was chartered by the state in 1871. Along with the U.S. Centennial in 1876, the city's industry was celebrated in the Centennial Exposition ,
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