Pittsburgh (/ˈpɪtsbərɡ/, PITS-burg) is the seat of Allegheny County and with a population of 305,841 is the second-largest city in the U.S. state of Pennsylvania. With a metropolitan CSA population of 2,659,937, it is 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. The city features 30 skyscrapers, 2 inclined railways, a pre-revolutionary fortification, and the source of the Ohio at the confluence of the Monongahela and Allegheny Rivers. This vital link of the Atlantic coast and Midwest cuts through the mineral-rich Alleghenies which made the area coveted by the French and British Empires, Virginia, Whiskey Rebels, Civil War raiders and media networks.
Known for steel, Pittsburgh also led innovations and industries in aluminum, glass, shipbuilding, petroleum, foods, appliances, sports, transportation, computing, retail, cars, and electronics. This creative wealth placed Pittsburgh third (after New York and Chicago) in corporate headquarters employment for much of the 20th century, second only to New York in bank assets and with the most U.S. stockholders per capita. America's 1980s deindustrialization laid off area blue-collar workers and thousands of downtown white-collar workers 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 industry center, its melting pot of immigrant workers, and top-10 rank among the largest U.S. cities until 1950 and metro areas until 1980 left the area with renowned museums, medical centers, parks, research centers, libraries, a vibrantly diverse cultural district and the most bars per capita in the U.S.
These legacies have earned Pittsburgh the title of America's Most Livable City by Places Rated Almanac, Forbes, and The Economist while having National Geographic and Today name the city a top world destination. Since 2004, the area has added over 3,000 hotel rooms with higher occupancy than 11 comparable cities.
Apple, Google, and Intel are among 1,600 technology firms generating $10.8 billion in annual Pittsburgh payrolls, with the area serving as the long-time federal agency headquarters for cyber defense, software engineering, robotics, energy research and the nuclear navy. R&D leaders Carnegie Mellon University and the University of Pittsburgh annually produce multiple startups as the area has earned the top rank as "America's smartest" with 68 colleges and universities.
The nation's fifth-largest bank, eight Fortune 500 companies, and six of the top 300 US law firms make their global headquarters in the Pittsburgh area, while RAND, BNY Mellon, Nova, Bayer, FedEx, GSK and NIOSH have large regional bases that helped Pittsburgh become the sixth-best area for U.S. job growth.
A leader in environmental design the city is home to 60 total and 10 of the world's first green buildings, even as billions have recently been invested in the area's Marcellus energy renaissance. A renaissance of Pittsburgh's 116-year-old film industry—that boasts the world's first movie theater—has grown from the long-running Three Rivers Film Festival to an influx of major productions including Disney and Paramount offices with the largest sound stage outside Los Angeles and New York.