- 1632 Galileo's Dialogue Concerning the Two Chief World Systems is published.
- 1774 British House of Lords rules authors do not have perpetual copyright
- 1797 The Last Invasion of Britain by the French, begins near Fishguard, Wales.
- 1825 Russia & Britain establish Alaska-Canada boundary
- 1967 25,000 US & South Vietnamese troops launch Operation Junction City against Viet Cong. Largest US airborne assult since WWII
1st national meeting of Republican Party (Pittsburgh)
On this day in 1856