Pittsburgh, located in the Commonwealth of Pennsylvania, is the county seat of Allegheny County and the most populous city in both Allegheny County and Western Pennsylvania. It ranks as the 68th-largest city in the United States, with a population of 302,971 according to the 2020 census. Pittsburgh serves as the anchor of the Greater Pittsburgh metropolitan area, with a population of 2.37 million. This figure makes it the largest population center in both the Ohio Valley and Appalachia, the second-largest in Pennsylvania, and the 27th-largest in the United States. Additionally, Pittsburgh is the principal city of the combined statistical area that encompasses greater Pittsburgh, New Castle, and Weirton, extending into Ohio and West Virginia.
Pittsburgh, an integral city of southwest Pennsylvania, sits at the merger of the Allegheny River and the Monongahela River, which amalgamate to form the Ohio River. This urban center has earned its reputation as the "Steel City" for its dominant contribution to the history of the U.S. steel industry, as well as the "City of Bridges" for its impressive 446 bridges. In addition, the city boasts 30 skyscrapers, two inclined railways, a pre-revolutionary fortification, and the Point State Park located at the confluence of the rivers. Pittsburgh's development is rooted in its critical position as a vital link between the Atlantic coast and Midwest. The mineral-rich Allegheny Mountains led to the region being hotly contested by the French and British empires, Virginians, Whiskey Rebels, and Civil War raiders.