Thirty-nine delegates signed the United States Constitution at Independence Hall on September 17, 1787.
The signers were delegates to the Constitutional Convention in Philadelphia. They represented 12 states because Rhode Island declined to send delegates. The convention had begun as an effort to revise the Articles of Confederation but produced an entirely new framework for the federal government.
The Constitution created a system built around legislative, executive, and judicial branches. George Washington presided over the convention, while James Madison, Alexander Hamilton, and other delegates argued over representation, federal powers, and the balance between state and national authority.
The number 39 is often confused with 55, the approximate number of delegates who attended the convention at some point. It is also distinct from the 56 signers of the Declaration of Independence. The Constitution was signed by 39 delegates, then sent to the states for ratification.