With a population of 306,211 Pittsburgh is the second-largest city in the U.S. state of Pennsylvania.
The metropolitan area has a population of 2,661,369, the largest in both the Ohio Valley and Appalachia and the 20th-largest in the U.S.
Pittsburgh is known as both "the Steel City" for its more than 300 steel-related businesses and "the City of Bridges" for its 446 bridges.
Known for steel, the city also led innovations and industries in many areas. This placed Pittsburgh third in corporate headquarters employment for much of the 20th century, second only to New York City in bank assets and with more stockholders per capita than any other U.S. city. America's 1980s deindustrialization laid off millions of blue-collar workers in the area, with thousands of downtown white-collar workers joining them after multi-billion-dollar corporate raids relocated the longtime Pittsburgh-based world headquarters of Gulf Oil, Sunbeam, Rockwell and Westinghouse.
This status as a global industrial and banking center, its "melting pot" of industrial immigrant workers, and top-10 rank among the largest cities in the U.S. until 1950 and metro areas until 1980 left the region with a plethora of internationally regarded museums, medical centers, parks, research infrastructure, libraries, and a vibrantly diverse cultural district.
These legacies have earned Pittsburgh the title of America's "most livable city" by Places Rated Almanac, Forbes, and The Economist while inspiring National Geographic and Today to name the city a top world destination.
The area of the Ohio headwaters was inhabited by the Shawnee and several other settled groups of native Americans. The first European was the French trader Robert de La Salle in his 1669 expedition down the Ohio River from Lake Ontario and Quebec. European pioneers, primarily Dutch, followed in the early 18th century. In 1717 European traders first became established in the area. In 1749, French soldiers from Quebec launched a serious expedition to the forks to unite Canada with French Louisiana via the rivers. The French and Indian War began with the future Pittsburgh as its center and in 1758 the French surrendered the forks. Construction began on Fort Pitt, named after British Secretary of State and soon-to-be Prime Minister William Pitt the Elder while the settlement was named "Pittsborough".
The War of 1812 cut off the supply of British goods, stimulating American manufacture. By 1815, Pittsburgh was producing significant quantities of iron, brass, tin and glass and in March, 1816 the 46 year old local government became a city. By the 1840s, Pittsburgh was one of the largest cities west of the Allegheny Mountains. The American Civil War boosted the city's economy with increased iron and armament production. By 1911 Pittsburgh was the nation's 8th largest city accounting for between a third and a half of national steel output. The city's population swelled to over a half million with European immigration via Ellis Island. By 1940, non-Hispanic whites were 90.6% of the city's population. Pittsburgh was a main destination of the African-American Great Migration with 95% percent becoming unskilled steel workers. World War II saw area mills operate 24 hours a day to produce 95 million tons of steel, but also recorded the highest levels of air pollution in its almost century of industry. The city's reputation as the "arsenal of democracy" was being overshadowed by James Parton's 1868 observation of Pittsburgh being "hell with the lid off".
Following the war, the city launched a clean air and civic revitalization project known as the "Renaissance" which was followed by a project in 1977 focusing on cultural and neighborhood development. Beginning in the early 1980s both the area's steel and electronics industries imploded, with massive layoffs from mill and plant closures.
In the latter 20th century the area shifted its economic base to education, tourism, and services, largely based on healthcare, finance and high technology such as robotics. Although Pittsburgh successfully shifted its economy and remained viable, the city's population never rebounded to its industrial-era highs. While 680,000 people lived in the city proper in 1950, a combination of suburbanization and economic turbulence caused a decrease in city population.