On September 25, 1789, the U.S. Congress passed twelve amendments to the United States Constitution: the Congressional Apportionment Amendment (which was never ratified), the Congressional Compensation Amendment, and the ten that are known as the Bill of Rights.
Many, many years earlier on that date, in 1555, the Peace of Augsburg was signed in Augsburg by Charles V and the princes of the Schmalkaldic League.