The city of Philadelphia, Pa., is located in Philadelphia County. The city of Philadelphia serves as the county seat of Philadelphia County, and is where the headquarters of the county offices are located.
Philadelphia is the largest city in the Commonwealth of Pennsylvania. The city, incorporated in 1701, was the temporary capital of the United States from 1790 to 1800. Philadelphia was the site of the signing of the Declaration of Independence and the Constitutional Convention, and was the home of many famous Americans, such as Benjamin Franklin and William Penn. Philadelphia County was founded by Penn in 1682, and is the most populated county in the state.