The 1787 United States Constitutional Convention met in Philadelphia, Pennsylvania.
Delegates gathered at the Pennsylvania State House, the building now known as Independence Hall. The convention formally opened on May 25, 1787, and continued through September 17. Although delegates were initially sent to revise the Articles of Confederation, they ultimately drafted an entirely new constitution.
George Washington presided over the meetings, while James Madison played a major role in preparing proposals and recording the debates. The proceedings were conducted in secrecy so delegates could negotiate freely. The resulting Constitution created a stronger federal government with separate legislative, executive, and judicial branches.
Philadelphia had already hosted the Second Continental Congress during the American Revolution and had been the scene of the Declaration of Independence. It was also the first capital of the United States under the Constitution, before the federal government moved to Washington, D.C.