Events
- 1788 – New Hampshire ratifies the Constitution and is thus admitted as the 9th state in the United States.
- 1813 – Laura Secord sets out to warn British forces of an impending U.S. attack on Queenston, Ontario during the War of 1812.
- 1877 – The Molly Maguires, ten Irish immigrants, are hanged at the Schuylkill County and Carbon County, Pennsylvania Prisons.
- 1898 – Guam becomes a U.S. territory.
- 1915 – The U.S. Supreme Court hands down its decision in Guinn v. United States 238 US 347 1915, striking down an Oklahoma law denying the right to vote to some citizens.
- 1942 – World War II: A Japanese submarine surfaces near the Columbia River in Oregon, firing 17 shells at nearby Fort Stevens in one of only a handful of attacks by the Japanese against the U.S. mainland.
- 1948 – The "Manchester Baby" (SSEM) runs the first ever computer program stored in electronic memory.
- 1948 – Columbia Records introduces the long-playing record album in a public demonstration at the Waldorf-Astoria Hotel in New York City.
- 1964 – Three civil rights workers, Andrew Goodman, James Chaney and Mickey Schwerner, are murdered in Neshoba County, Mississippi, United States, by members of the Ku Klux Klan.
- 1973 – In handing down the decision in Miller v. California 413 US 15, the Supreme Court of the United States establishes the Miller Test, which now governs obscenity in U.S. law.
- 1982 – John Hinckley is found not guilty by reason of insanity for the attempted assassination of U.S. President Ronald Reagan.
- 2001 – A federal grand jury in Alexandria, Va., indicted 13 Saudis and a Lebanese in the 1996 bombing of the Khobar Towers in Saudi Arabia that killed 19 American servicemen.
- 2004 – SpaceShipOne becomes the first privately funded spaceplane to achieve spaceflight.