1862: During the Civil War, the Battle of Antietam took place in Maryland near Antietam Creek.

1787: Delegations from 12 states voted unanimously to approve the U.S. Constitution. Thirty-nine of the 42 delegates signed it so the Constitutional Convention being held in Philadelphia adjourned. Library of Congress: Two days earlier, when a final vote was called, Edmund Randolph called for another convention to carefully review the Constitution as it stood. This motion, supported by George Mason and Elbridge Gerry, was voted down and the Constitution was adopted. The product of four months of secret debate, the Constitution replaced the Articles of Confederation and proposed an entirely new form of government. Adopted by the Continental Congress in 1777, but not ratified by the states until 1781, the Articles of Confederation created a loose confederation of sovereign states and a weak central government.