McKeesport is a city in Allegheny County in the U.S. state of Pennsylvania; it is situated at the confluence of the Monongahela and Youghiogheny rivers and is part of the Pittsburgh Metro Area. The population was 19,731 at the 2010 census. It is the second-largest city in the county after Pittsburgh. Settled in 1795 and named in honor of John McKee, its founder, McKeesport remained a village until 1830 when coal mining began in the region. Large deposits of bituminous coal existed.