Philadelphia is the largest city in the Commonwealth of Pennsylvania and the fifth-most populous city in the United States, with an estimated population of 1,567,442 and more than 6 million in the seventh-largest metropolitan statistical area, as of 2015. Philadelphia is the economic and cultural anchor of the Delaware Valley—a 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, particularly from Ireland and Italy. It became a prime destination for Black Americans and Puerto Ricans in the Great Migration and surpassed two million occupants by 1950.
Philadelphia is home to many national historical sites that relate to the founding of the United States. Independence National Historical Park is the center of these historical landmarks being one of the country’s 22 UNESCO World Heritage Sites. Independence Hall, where the Declaration of Independence was signed, and the Liberty Bell are the city’s most famous attractions. Other historic sites include homes for Edgar Allan Poe, Betsy Ross, and Thaddeus Kosciuszko, early government buildings like the First and Second Banks of the United States, Fort Mifflin, and the Gloria Dei (Old Swedes’) Church. Philadelphia alone has 67 National Historic Landmarks, the third most of any city in the country.