Philadelphia is the largest city in the Commonwealth of Pennsylvania and the sixth-most populous city in the United States, with an estimated population of 1,567,872 and more than 6 million in the seventh-largest metropolitan statistical area,. Philadelphia is the economic and cultural anchor of the Delaware Valleya region located in the Northeastern United States at the confluence of the Delaware and Schuylkill Rivers with 7.2 million people residing in the eighth-largest combined statistical area in the United States.In 1682, William Penn, an English Quaker, founded the city to serve as capital of the Pennsylvania Colony. Philadelphia played an instrumental role in the American Revolution as a meeting place for the Founding Fathers of the United States, who signed the Declaration of Independence in 1776 and the Constitution in 1787. Several other key Philadelphia events during the Revolution include the First and Second Continental Congress, the preservation of the Liberty Bell, the Battle of Germantown, the Siege of Fort Mifflin, and the Philadelphia Convention. Philadelphia was one of the nation's capitals in the Revolutionary War, and served as temporary U.S. capital while Washington, D.C., was under construction. In the 19th century, Philadelphia became a major industrial center and railroad hub that grew from an influx of European immigrants. The majority of European immigrants have come from Ireland, Italy and Germany—the three largest reported ancestry groups in the city. The city became a prime destination for African Americans during the Great Migration of the 20th century, as well as Puerto Ricans, surpassing two million occupants by 1950.
