Who was unanimously elected presiding officer of the 1787 Constitutional Convention?

George Washington was unanimously elected presiding officer of the 1787 Constitutional Convention.

The convention met in Philadelphia from May to September 1787. Delegates initially gathered to improve the Articles of Confederation, but they soon decided to design an entirely new federal system. Washington's reputation as commander of the Continental Army and first president of the Confederation Congress made him a powerful choice to chair the proceedings.

As presiding officer, Washington generally maintained order and limited his participation in debate. He did not write the Constitution, and his chairmanship should not be confused with the major drafting roles played by James Madison, the Committee of Detail, and the Committee of Style. Benjamin Franklin was the convention's oldest delegate and an influential supporter of compromise, but he was not its presiding officer.

The convention signed the Constitution on September 17, 1787. It then went to the states for ratification. Washington became the first president under the new Constitution in 1789, after previously serving as the nation's leading military figure during the Revolution.