- 1609 – Henry Hudson is the first European to visit Manhattan Island.
- 1777 – Troops commanded by Gen. George Washington were defeated by the British in the Battle of Brandywine.
- 1789 – Alexander Hamilton is appointed the first Secretary of the Treasury.
- 1813 – British troops arrive in Mount Vernon and prepare to invade Washington, D.C. during the War of 1812.
- 1950 – Korean War: President Harry S. Truman approved military operations north of the 38th parallel.
- 1959 – Congress passed a bill authorizing food stamps for low-income Americans.
- 1978 – Janet Parker, a British medical photographer, became the last recorded person to die from smallpox.
- 2001 – September 11 attacks: A series of coordinated suicide attacks killing 2,996 people. Two aircraft crash into the World Trade Center in New York City, a third hits The Pentagon, and a fourth into a field near Shanksville, Pennsylvania.
- 2012 – The U.S. embassy in Benghazi, Libya is attacked, resulting in four deaths.
