IntroductionPittsburgh (pĭtsˈbərg) [key], city (1990 pop. 369,879), seat of Allegheny co., SW Pa., at the confluence of the Allegheny and the Monongahela rivers, which there form the Ohio River; inc. 1816. A major inland port of entry, it is located at the junction of east-west transportation arteries.
See more Encyclopedia articles on: U.S. Political Geography