1609 – Henry Hudson discovers Manhattan and the indigenous people living there.
1789 – Alexander Hamilton is appointed the first Secretary of the Treasury.
1857 – The Mountain Meadows massacre: Mormon settlers and Paiutes massacre 120 pioneers at Mountain Meadows, Utah.
1944 – The Allied invasion of Germany begins near the city of Aachen.
1950 – President Harry Truman approved military operations north of the 38th paralell during the Korean War.
2001 – Two hijacked aircraft crash into the World Trade Center in New York City, while a third smashes into The Pentagon, and a fourth into a field near Shanksville, Pennsylvania in a series of coordinated suicide attacks by 19 members of al-Qaeda. A total of 2,996 people are killed.
2012 – The U.S. embassy in Benghazi, Libya is attacked, resulting in four deaths.