Events
- 1769 – Father Junípero Serra founds Mission San Diego de Alcalá, the first mission in California. The mission later evolves into the city of San Diego.
- 1790 – The signing of the Residence Bill establishes a site along the Potomac River as the District of Columbia (seat of government).
- 1862 – American Civil War: David G. Farragut becomes the first United States Navy rear admiral.
- 1941 – New York Yankees' Joe DiMaggio gets a hit in his 56th consecutive game.
- 1945 – Manhattan Project: The Atomic Age begins when the United States successfully detonates a plutonium-based test nuclear weapon at the Trinity site near Alamogordo, New Mexico.
- 1955 – Original Disneyland park opens in Anaheim, California.
- 1957 – United States Marine Major John Glenn flies a F8U Crusader supersonic jet from California to New York in 3 hours, 23 minutes and 8 seconds, setting a new transcontinental speed record.
- 1969 – Apollo program: Apollo 11 is launched from Cape Kennedy, Florida, and will become the first manned space mission to land on the Moon.
- 1973 – Watergate scandal: Former White House aide Alexander P. Butterfield informs the United States Senate that President Richard Nixon had secretly recorded potentially incriminating conversations.
- 1999 – John F. Kennedy Jr., his wife Carolyn Bessette Kennedy, and sister-in-law Lauren Bessette are killed in a plane crash off the coast of Martha's Vineyard. The Piper Saratoga aircraft was piloted by Kennedy.
- 2004 – Millennium Park, considered the first and most ambitious architectural project in the early 21st century for Chicago, is opened to the public by Mayor Richard M. Daley.