Which two signers of the Declaration of Independence died on July 4, 1826?

Thomas Jefferson and John Adams, both signers of the Declaration of Independence, died on July 4, 1826.

Their deaths occurred exactly 50 years after Congress adopted the Declaration. Jefferson died at Monticello in Virginia, while Adams died at his home in Quincy, Massachusetts. The coincidence became one of the most famous anniversaries in United States history.

Adams's reported last words included the belief that Jefferson still lived, unaware that Jefferson had died earlier that day. Jefferson and Adams had been political allies during the independence movement, later opponents in the 1796 presidential election, and eventually correspondents again.

They were the only two signers of the Declaration who later became presidents of the United States. The coincidence concerns the date of their deaths, not the date on which every delegate signed the document.