Pittsburgh ( ) is a city in Allegheny County, Pennsylvania, United States, and its county seat. Located in southwestern Pennsylvania where the Allegheny and Monongahela Rivers meet to form the Ohio River, it had a population of 302,971 at the 2020 census, making it the second-most populous city in Pennsylvania after Philadelphia. The Pittsburgh metropolitan area has over 2.43 million people, making it the largest in the Ohio Valley and Appalachia, the second-largest in Pennsylvania, and the 28th-largest in the U.S. The greater Pittsburgh–Weirton–Steubenville combined statistical area includes parts of Ohio and West Virginia.
Pittsburgh is known as "the Steel City" for its dominant role in the history of the U.S. steel industry. It developed as a vital link of the Atlantic coast and Midwest, as the mineral-rich Allegheny Mountains led to the region being contested by the French and British empires, Virginians, Whiskey Rebels, and Civil War raiders. For part of the 20th century, Pittsburgh was behind only New York City and Chicago in corporate headquarters employment; it had the most U.S. stockholders per capita. Deindustrialization in the late 20th century resulted in massive layoffs among blue-collar workers as steel and other heavy industries declined, coinciding with several Pittsburgh-based corporations moving out of the city. However, the city divested from steel and, since the 1990s, Pittsburgh has focused its energies on the healthcare, education, and technology industries.
Pittsburgh is home to large medical providers, including the University of Pittsburgh Medical Center and Allegheny Health Network, as well as 68 colleges and universities, including Carnegie Mellon University and the University of Pittsburgh. The area has served as the federal agency headquarters for cyber defense, software engineering, robotics, energy research, and the nuclear navy. The city is home to ten Fortune 500 companies and seven of the largest 300 U.S. law firms.
Pittsburgh is sometimes called the "City of Bridges" for its 446 bridges.
Pittsburgh was incorporated as a borough on April 22, 1794, with the following Act:
"Be it enacted by the Pennsylvania State Senate and Pennsylvania House of Representatives of the Commonwealth of Pennsylvania ... by the authority of the same, that the said town of Pittsburgh shall be ... erected into a borough, which shall be called the borough of Pittsburgh for ever."
From 1891 to 1911, the city's name was federally recognized as "Pittsburg", though use of the final h was retained during this period by the city government and other local organizations.
History
Native Americans
The area of the Ohio headwaters was long inhabited by the Shawnee and several other settled groups of Native Americans. The Seneca people called the confluence of the rivers Diondega or Jaödeogë’. Shannopin's Town was an 18th-century Lenape (Delaware) town located roughly from where Penn Avenue is today, below the mouth of Two Mile Run, from 30th Street to 39th Street. According to George Croghan, the town was situated on the south bank of the Allegheny, nearly opposite what is now known as Washington's Landing, formerly Herr's Island, in what is now the Lawrenceville neighborhood.
18th century
thumb|left|[[Fort Pitt Block House, built by the British in 1764, is the oldest extant structure in Pittsburgh.]]
The first known European to enter the region was the French explorer Robert de La Salle from Quebec during his 1669 expedition down the Ohio River. European pioneers, primarily Dutch, followed in the early 18th century. Michael Bezallion was the first to describe the forks of the Ohio in a 1717 manuscript, and later that year European fur traders established area posts and settlements.
In 1749, French soldiers from Quebec launched an expedition to the forks to unite Canada with French Louisiana via the rivers. The British and colonial force were defeated at Braddock's Field. General John Forbes finally took the forks in 1758. He began construction on Fort Pitt, named after William Pitt the Elder, while the settlement was named "Pittsborough".
During Pontiac's War, a loose confederation of Native American tribes laid siege to Fort Pitt in 1763; the siege was eventually lifted after Colonel Henry Bouquet defeated a portion of the besieging force at the Battle of Bushy Run. Bouquet strengthened the defenses of Fort Pitt the next year.
During this period, the powerful nations of the Iroquois Confederacy, based in New York, had maintained control of much of the Ohio Valley as hunting grounds by right of conquest after defeating other tribes. By the terms of the 1768 Treaty of Fort Stanwix, the Penns were allowed to purchase the modern region from the Iroquois. A 1769 survey referenced the future city as the "Manor of Pittsburgh". Both the Colony of Virginia and the Province of Pennsylvania claimed the region under their colonial charters until 1780, when they agreed under a federal initiative to extend the Mason–Dixon line westward, placing Pittsburgh in Pennsylvania. On March 8, 1771, Bedford County, Pennsylvania was created to govern the frontier.
On April 16, 1771, the city's first civilian local government was created as Pitt Township. William Teagarden was the first constable, and William Troop was the first clerk.
Following the American Revolution, the village of Pittsburgh continued to grow. One of its earliest industries was boat building for settlers of the Ohio Country. In 1784, Thomas Vickroy completed a town plan which was approved by the Penn family attorney. Pittsburgh became a possession of Pennsylvania in 1785. The following year, the Pittsburgh Post-Gazette was started, and in 1787, the Pittsburgh Academy was chartered. Unrest during the Whiskey Rebellion of 1794 resulted in federal troops being sent to the area. By 1797, glass manufacture began, while the population grew to around 1,400. Settlers arrived after crossing the Appalachian Mountains or through the Great Lakes. Fort Pitt (now Pittsburgh) at the source of the Ohio River became the main base for settlers moving into the Northwest Territory.
19th century
The federal government recognizes Pittsburgh as the starting point for the Lewis and Clark Expedition. Preparations began in Pittsburgh in 1803 when Meriwether Lewis purchased a keelboat that would later be used to ascend the Missouri River.
The War of 1812 cut off the supply of British goods, stimulating American industry. By 1815, Pittsburgh was producing significant quantities of iron, brass, tin, and glass. On March 18, 1816, the 46-year-old local government became a city. It was served by numerous river steamboats that increased trading traffic on the rivers.
In the 1830s, many Welsh people from the Merthyr steelworks immigrated to the city following the aftermath of the Merthyr Rising. By the 1840s, Pittsburgh was one of the largest cities west of the Allegheny Mountains. The Great Fire of Pittsburgh destroyed over a thousand buildings in 1845. The city rebuilt with the aid of Irish immigrants who came to escape the Great Famine. By 1857, Pittsburgh's 1,000 factories were consuming 22 million coal bushels yearly. Coal mining and iron manufacturing attracted waves of European immigrants to the area, with the most coming from Germany.
thumb|Burning of Union Depot during the [[Pittsburgh railroad strike of 1877]]
Because Pennsylvania had been established as a free state after the Revolution, enslaved African Americans sought freedom here through escape as refugees from the South, or occasionally fleeing from travelers they were serving who stayed in the city. There were active stations of the Underground Railroad in the city, and numerous refugees were documented as getting help from station agents and African-American workers in city hotels. The Drennen Slave Girl walked out of the Monongahela House in 1850, apparently to freedom. The Merchant's Hotel was also a place where African-American workers would advise slaves the state was free and aid them in getting to nearby stations of the Underground Railroad.
Sometimes refugee slaves from the South stayed in Pittsburgh, but other times they continued North, including into Canada. Many slaves left the city and county for Canada after Congress passed the 1850 Fugitive Slave Act, as it required cooperation from law enforcement even in free states and increased penalties. From 1850 to 1860, the black population in Allegheny County dropped from 3,431 to 2,725 as people headed to safety in Canada.
| image2 = Mills in Strip District, Pittsburgh (84.41.70).jpg
| caption2 = Steel mills in the Strip District in 1906
In 1901, J. P. Morgan and attorney Elbert H. Gary merged Carnegie Steel Company and several other companies into U.S. Steel. By 1910, Pittsburgh was the nation's eighth-largest city, accounting for between one-third and one-half of national steel output.
The Pittsburgh Agreement was a memorandum of understanding completed on 31 May 1918 between members of Czech and Slovak expatriate communities in the U.S. It replaced the Cleveland Agreement of 22 October 1915. It concerned the future foundation of Czechoslovakia as envisioned by T. G. Masaryk.
The city suffered severe flooding in March 1936. On March 17 and 18, Pittsburgh sustained its worst flood in history as flood levels rose to a peak of 46 feet. Days of heavy rain and melting snow poured into the city's waterways. At least 62 people died from this tragedy.
The city's population swelled to more than a half million, attracting numerous European immigrants to its industrial jobs. By 1940, non-Hispanic whites were 90.6% of the city's population. Pittsburgh also became a main destination of the African-American Great Migration from the rural South during the first half of the 20th century. Limited initially by discrimination, some 95% percent of the men became unskilled steel workers.
During World War II, demand for steel increased and area mills operated 24 hours a day to produce 95 million tons of steel for the war effort. was being overshadowed by James Parton's 1868 observation of Pittsburgh being "hell with the lid off."
Following World War II, the city launched a clean air and civic revitalization project known as the "Renaissance," cleaning up the air and the rivers. The "Renaissance II" project followed in 1977, focused on cultural and neighborhood development. The industrial base continued to expand through the 1970s, but beginning in the early 1980s both the area's steel and electronics industries imploded during national industrial restructuring. There were massive layoffs from mill and plant closures.
In September 2009, the 2009 G20 Pittsburgh summit was held in Pittsburgh.
Geography
thumb|The [[Duquesne Incline from Mount Washington]]
Pittsburgh has an area of , of which is land and , or 4.75%, is water. The 80th meridian west passes directly through the city's downtown.
The city is located on the Allegheny Plateau, within the ecoregion of the Western Allegheny Plateau. The Downtown area (also known as the Golden Triangle) sits where the Allegheny River flows from the northeast and the Monongahela River from the southeast to form the Ohio River. The convergence is at Point State Park and is referred to as "the Point". The city extends east to include the Oakland and Shadyside sections, which are home to the University of Pittsburgh, Carnegie Mellon University, Chatham University, Carnegie Museum and Library, and many other educational, medical, and cultural institutions. The southern, western, and northern areas of the city are primarily residential.
Many Pittsburgh neighborhoods are steeply sloped with two-lane roads. More than a quarter of neighborhood names make reference to "hills", "heights", or similar features.
The steps of Pittsburgh consist of 800 sets of outdoor public stairways with 44,645 treads and 24,090 vertical feet. They include hundreds of streets composed entirely of stairs, and many other steep streets with stairs for sidewalks. Many provide vistas of the Pittsburgh area while attracting hikers and fitness walkers.
Bike and walking trails have been built to border many of the city's rivers and hollows. The Great Allegheny Passage and Chesapeake and Ohio Canal Towpath connect the city directly to downtown Washington, D.C. (some away) with a continuous bike/running trail.
Cityscape
thumb|Pittsburgh's [[List of Pittsburgh neighborhoods|90 distinct neighborhoods]]
thumb|East Carson Street in the [[South Side Flats]]
thumb|[[Shadyside (Pittsburgh)|Shadyside neighborhood]]
The city consists of the Downtown area, called the Golden Triangle, and four main areas surrounding it—Central, North Side/North Hills, South Side/South Hills, East End, and West End. These areas are further divided into 90 neighborhoods.
Downtown Pittsburgh has 30 skyscrapers, nine over , with the U.S. Steel Tower being the tallest at . The Cultural District spans 14 blocks along the Allegheny River and is home to theaters, arts venues, and a growing residential community. The Firstside portion of Downtown borders the Monongahela River, the historic Mon Wharf and hosts the distinctive PPG Place Gothic-style glass skyscraper complex. Downtown is served by the Port Authority's light rail system and multiple bridges leading north and south. It is also home to Point Park University and Duquesne University which borders Uptown.
The North Side, originally the independent Allegheny City until being annexed in 1907, is a primarily residential area with well-preserved 19th-century homes. It hosts attractions like Acrisure Stadium, PNC Park, the Andy Warhol Museum, and the National Aviary, among others.
The South Side, once home to railyards and mill workers, has seen revitalization with improvements to East Carson Street and new retail. It is now a vibrant neighborhood with diverse shopping and nightlife. In the 1990s, the Urban Redevelopment Authority of Pittsburgh purchased the South Side Works steel mill property and redeveloped it into the SouthSide Works mixed-use development.
The East End includes key institutions including the University of Pittsburgh, Carnegie Mellon University, Carnegie Museums of Art and Natural History, and Phipps Conservatory. It features many parks, including Mellon Park, Westinghouse Park, Schenley Park, Frick Park, The Frick Pittsburgh, Bakery Square, and the Pittsburgh Zoo, and vibrant neighborhoods like Shadyside. Squirrel Hill is also known as the hub of Jewish life in Pittsburgh, home to approximately 20 synagogues. Oakland is home to several universities and the Petersen Events Center. The Strip District to the west along the Allegheny River is an open-air marketplace by day and a clubbing destination by night. Bloomfield is Pittsburgh's Little Italy and is known for its Italian restaurants and grocers. Lawrenceville is a revitalizing rowhouse neighborhood popular with artists and designers. The Hill District was home to photographer Charles Harris as well as various African-American jazz clubs.
The West End includes Mt. Washington, with its famous view of the downtown skyline, and numerous other residential neighborhoods such as Sheraden and Elliott.
alt=Panorama of Pittsburgh, PA|center|thumb|750x750px|Pittsburgh seen from [[Mount Washington, Pittsburgh (mountain)|Mount Washington at night with the Monongahela River in the foreground in November 2015]]
Regional identity
thumb|alt=The Puddler, a glass mural of an iron or steel worker in downtown Pittsburgh|The Puddler, a glass mural of an iron or steel worker, memorializing Pittsburgh's [[industrial heritage]]
Pennsylvania lies within the Northeastern United States as defined by U.S. Census Bureau regional classifications, which are used primarily for administrative and statistical purposes rather than cultural identification.
Pittsburgh lies within the boundaries of Appalachia as designated by the Appalachian Regional Commission, and has long been characterized as a northern urban industrial anchor of Appalachia. In its post-industrial era, Pittsburgh has been described as the "Paris of Appalachia", in reference to the city's cultural, educational, healthcare, and technological resources. It is the largest city within the Appalachian region.
Geographer Joseph Scarpaci has described Pittsburgh's regional identity as bridging Northeastern and Midwestern influences, characterizing the city as having “one foot in the East... and the other in the Midwest.”
Pittsburgh is the principal city of the Pittsburgh Combined Statistical Area, a combined statistical area defined by the U.S. Census Bureau.
Climate
Under the Köppen climate classification, Pittsburgh falls within either a hot-summer humid continental climate (Dfa) if the isotherm is used or a humid subtropical climate (Cfa) if the isotherm is used. Summers are hot and winters are moderately cold with wide variations in temperature. Despite this, it has one of the most pleasant summer climates between medium and large cities in the U.S. The city lies in the USDA plant hardiness zone 6b except along the rivers where the zone is 7a. The area has four distinct seasons: winters are cold and snowy, springs and falls are mild with moderate levels of sunshine, and summers are warm. As measured by percent possible sunshine, summer is by far the sunniest season, though annual sunshine is low among major US cities at well under 50%. On average, December and January have the greatest number of precipitation days. Snowfall averages per season, but has historically ranged from in 1918–19 to in 1950–51. There is an average of 59 clear days and 103 partly cloudy days per year, while 203 days are cloudy. In terms of annual percent-average possible sunshine received, Pittsburgh (45%) is similar to Seattle (49%).
Air quality
United States Environmental Protection Agency (EPA) data from 2021 to 2024 shows that Pittsburgh's air quality was generally good or moderate.
Despite improvements, studies suggest Pittsburgh's air quality still impacts health. A 2014 to 2016 study found that children near pollution sources like industrial sites had asthma rates nearly three times the national average. It also revealed that 38% of students lived in areas exceeding EPA's particle pollution standards, and 70% in areas surpassing the WHO's standards.
As of 2005, Pittsburgh had 31,000 trees along 900 miles of streets. A 2011 analysis valued the annual benefits of the city's urban forest between $10 and $13 million, based on contributions to aesthetics, energy use, and air quality. The city invests $850,000 annually in tree planting and maintenance.
Water quality
Local rivers in Pittsburgh continue to exceed EPA pollution limits, primarily due to frequently overflowing untreated sewage from the city's outdated infrastructure. Pittsburgh's combined sewer system, built in the early 1900s, carries both stormwater and wastewater, with the treatment plant constructed in 1959. Insufficient upgrades have led to public health concerns, as even a tenth of an inch of rain causes runoff to flow into rivers. Nine billion gallons of untreated waste and stormwater flow into rivers per year, leading to health hazards and Clean Water Act violations. The Allegheny County Sanitary Authority (ALCOSAN) is under a Consent Decree from the EPA and proposed a $2 billion system upgrade in 2017, approved by the EPA in 2019.
Pittsburgh Water, the municipal water and sewer authority that serves most of the city and is responsible for maintaining infrastructure, replacing pipes, and setting water rates, has faced criticism for alleged mismanagement and for high lead levels in the city's drinking water, particularly in 2016. While lead levels had risen for years, at the time, many residents blamed the authority's administrative changes for the 2016 spike. In response, Pittsburgh Water began adding orthophosphate, a food-grade additive that helps prevent lead pipes from corroding into drinking water, to the water treatment process. Pittsburgh Water has also been working to replace residential lead service lines, citing a goal of 2027 by which to have replaced every residential lead line in its service area, and continuing to test water for lead. Some people, particularly during and after the 2016 lead crisis, also believe that the high levels of lead reflect environmental racism, as black and Hispanic children in Pittsburgh experience elevated blood-lead levels at 4 times the rate of white children.