Events
- 1722 – Three Years' War (Father Rale's War) begins along Maine and Massachusetts border.
- 1759 – French and Indian War: In Western New York, British forces capture Fort Niagara from French, who subsequently abandon Fort Rouillé.
- 1814 – War of 1812: Battle of Lundy's Lane – Reinforcements arrive near Niagara Falls for General Riall's British and Canadian forces and a bloody, all–night battle with Jacob Brown's Americans commences at 18.00; Americans retreat to Fort Erie.
- 1853 – Joaquin Murrieta, famous Californio bandit known as "Robin Hood of El Dorado", is killed.
- 1861 – American Civil War: The Crittenden–Johnson Resolution is passed by the U.S. Congress stating that the war is being fought to preserve the Union and not to end slavery.
- 1866 – The U.S. Congress passes legislation authorizing the rank of General of the Army (now called "5–star general"). Lieutenant General Ulysses S. Grant becomes the first to have this rank.
- 1868 – Wyoming becomes a United States territory.
- 1897 – Writer Jack London sails to join the Klondike Gold Rush where he will write his first successful stories.
- 1898 – The United States invasion of Puerto Rico begins with U.S. troops landing at harbor of Guánica, Puerto Rico [The land invasion, proper, began that day: Sea–based bombardment and shelling of the capital city of San Juan had been occurring since May 1898].
- 1946 – Operation Crossroads: An atomic bomb is detonated underwater in the lagoon of Bikini Atoll.
- 1946 – At Club 500 in Atlantic City, New Jersey, Dean Martin and Jerry Lewis stage their first show as a comedy team.
- 1952 – The U.S. non–incorporated colonial territory of Puerto Rico adopts a "constitution" of local–limited powers, approved by the United States Congress in contravention of then–current international law.
- 1961 – John F. Kennedy speech emphasizes that any attack on Berlin is an attack on NATO.
- 1969 – Vietnam War: US President Richard Nixon declares the Nixon Doctrine, stating that the United States now expects its Asian allies to take care of their own military defense. This was the start of the "Vietnamization" of the war.