The Republican Party nominated Abraham Lincoln for president at the 1860 Republican National Convention.
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President Franklin D. Roosevelt signed Tennessee Valley Act to build dams.
Northern Somalia declared its independence, becoming the unrecognized de facto Republic of Somaliland.
Apollo 10 was launched from the John F. Kennedy Space Center on a mission to the Moon.
John Bellingham was sentenced to death for assassinating Spencer Perceval, the British Prime Minister.
The Crusaders lost control of the city of Acre, the Kingdom of Jerusalem's last bastion, after a fourteen-day siege.