Philadelphia hosted the 1787 Constitutional Convention that drafted the U.S. Constitution.
Delegates met in the Pennsylvania State House, now known as Independence Hall, from May 25 to September 17, 1787. The gathering had originally been called to revise the Articles of Confederation, but it instead produced an entirely new framework for the federal government.
Philadelphia was already a major political and commercial center. It had hosted the Continental Congress and the Declaration of Independence, making it a familiar national meeting place before Washington, D.C., existed as the permanent capital.
The convention’s debates produced compromises over representation, taxation, slavery, executive power, and the relationship between the states and the federal government. The Constitution was signed on September 17 and then sent to the states for ratification. Independence Hall remains the best-known physical setting associated with both the nation’s founding declaration and its governing charter.