For America250, Philadelphia hosted the Constitutional Convention that produced the United States Constitution in 1787.
Delegates met from May 25 to September 17, 1787, in the Pennsylvania State House, the building now known as Independence Hall. The convention was originally called to revise the Articles of Confederation, but delegates instead designed an entirely new framework for the federal government. George Washington presided over the meetings.
The convention created compromises over representation, taxation, commerce, slavery, and the balance between state and national authority. The resulting Constitution established three branches of government and a system of federalism. Thirty-nine delegates signed the final document on September 17, although all convention delegates did not sign.
Philadelphia had already been central to the Declaration of Independence and the Revolutionary War. It later served as the temporary national capital before the government moved to Washington, D.C. The Constitutional Convention’s location is sometimes confused with the city where the Constitution was ratified; ratification occurred through state conventions rather than at one single national meeting.