Pittsburgh (/ˈpɪtsbərɡ/, PITS-burg) is the seat of Allegheny County and with a population of 306,211 is the second-largest city in the U.S. State of Pennsylvania. With a metropolitan CSA population of 2,661,369, 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 world-record 446 bridges. The city also features 29 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 the 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 its 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 City and Chicago) in corporate headquarters jobs 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 deindustrialization in the 1980s 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. Since 2004, the area has added 3,304 hotel rooms and has 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 city serving as national headquarters of the federal cyber defense, software engineering, robotics, atomic power and energy research agencies for decades. R&D leaders Carnegie Mellon University and the University of Pittsburgh annually produce multiple startups, ranking Pittsburgh as "America's smartest city" with 68 area colleges and universities, 38 of them non-profit.
The nation's fifth-largest bank, nine 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 metro area for U.S. job growth. Area retail and housing have also grown with the multi-million-dollar SouthSide Works, Bakery Square, and Washington's Landing repurposing former industrial sites.
Pittsburgh is a leader in environmental design with 60 total and 10 of the world's first green buildings, including downtown's convention center, even as billions have recently been invested in the area's energy renaissance with Marcellus shale. A renaissance of Pittsburgh's 115-year-old film industry—that boasts the world's first movie theater—has grown from the long-running 3R Film Festival to an influx of major productions including Disney and Paramount offices with the largest sound stage outside Los Angeles and New York.