About Philadelphia

Philadelphia, often called Philly, is the largest city in the Commonwealth of Pennsylvania and the second-largest city in both the Northeast megalopolis and Mid-Atlantic regions after New York City. It is one of the most historically significant cities in the United States and served as the nation's capital city until 1800. The city's population at the 2020 census was 1,603,797. Since 1854, the city has been coextensive with Philadelphia County, the most populous county in Pennsylvania and the urban core of the Delaware Valley, the nation's seventh-largest and one of the world's largest metropolitan regions with 6.245 million residents in 2020. Philadelphia is known for its extensive contributions to American history and for its role in the life sciences, business and industry, art, literature, and music.Philadelphia was founded in 1682 by William Penn, an English Quaker and advocate of religious freedom.