Who was the oldest person to sign the United States Constitution?

Benjamin Franklin was the oldest person to sign the United States Constitution.

Franklin was 81 years old when he signed the document on September 17, 1787. He represented Pennsylvania and was one of the most internationally famous American statesmen at the Constitutional Convention.

Franklin's health was poor during the convention, and he was sometimes carried into Independence Hall in a sedan chair. On the final day, James Wilson read an address on Franklin's behalf supporting the Constitution despite its imperfections. Franklin's intervention helped encourage the delegates to endorse the compromise document.

Franklin was also the oldest signer by a wide margin. Jonathan Dayton of New Jersey, aged 26, was the youngest. Thomas Jefferson and John Adams did not sign because both were serving abroad as diplomats, while George Washington presided over the convention and signed first.