- 1492 Christopher Columbus sets sail on his first voyage with three ships, Santa María, Pinta and Niña from Palos de la Frontera, Spain for the "Indies"
- 1596 David Fabricius discovers light variation of Mira (1st variable star)
- 1914 Germany invades Belgium and declares war on France, beginning World War I
- 1934 Adolf Hitler merges the offices of German Chancellor and President, declaring himself "Führer" (leader)
- 1972 U.S. Senate ratifies the Anti-Ballistic Missile Treaty.
- 1995 CNN en Espanol premieres
- 1958 The Billboard Hot 100 is founded
- 1949 Basketball Association of America (BAA) & National Basketball League (NBL) merge to form National Basketball Association (NBA), Maurice Podoloff elected head of new league
- 2017 Brazilian soccer forward Neymar transfers from FC Barcelona to Paris Saint-Germain for a world-record transfer fee of €222 on a 5-year deal
First known letter sent from North America by John Rut while at St. John's, Newfoundland
On August 3, 1527
South African government bans Beatle records
On August 3, 1966