Harrisburg is the capital city of the Commonwealth of Pennsylvania in the United States, and the county seat of Dauphin County. With a population of 48,904, it is the ninth-largest city in the Commonwealth. It lies on the east bank of the Susquehanna River, 107 miles west of Philadelphia.The Harrisburg-York-Lebanon, PA Combined Statistical Area is made up of six counties in south central Pennsylvania. As of the 2010 United States Census the CSA had a population total of 1,219,422, and ranked 3rd most populous in the state of Pennsylvania, after Philadelphia and Pittsburgh and 43rd most populous in the United States.Harrisburg played a notable role in American history during the Westward Migration, the American Civil War, and the Industrial Revolution. During part of the 19th century, the building of the Pennsylvania Canal and later the Pennsylvania Railroad allowed Harrisburg to become one of the most industrialized cities in the Northeastern United States. The U.S.