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 (which was later enacted as the Twenty-seventh Amendment), and the ten that are known as the Bill of Rights.
Centuries earlier on that date, in 1555, the Peace of Augsburg was signed in Augsburg by Charles V and the princes of the Schmalkaldic League.