George Washington presided over the Constitutional Convention that drafted the United States Constitution.
The convention met in Philadelphia from May 25 to September 17, 1787. Delegates had originally been asked to revise the Articles of Confederation, but they ultimately designed an entirely new federal system. They unanimously elected Washington as the convention's presiding officer.
Washington rarely took part in debates, but his presence gave the proceedings authority. He had commanded the Continental Army during the Revolutionary War and was widely respected by delegates from different states. His role as chair was distinct from James Madison's role as a leading planner and major contributor to the convention's ideas.
The convention produced the Constitution, which 39 of the 55 delegates present signed on September 17, 1787. Washington later became the first president under that Constitution. Benjamin Franklin was another delegate and influential elder statesman, but Washington—not Franklin or Madison—presided.