332 – Constantine the Great announced free distributions of food to the citizens in Constantinople.
1593 – Playwright Thomas Kyd’s accusations of heresy lead to an arrest warrant for Christopher Marlowe.
1652 – Rhode Island passes the first law in English-speaking North America making slavery illegal.
1860 – Abraham Lincoln wins the Republican Party presidential nomination over William H. Seward, who later becomes the United States Secretary of State.
1896 – The United States Supreme Court rules in Plessy v. Ferguson that the “separate but equal” doctrine is constitutional.
1917 – World War I: The Selective Service Act of 1917 is passed, giving the President of the United States the power of conscription.
1965 – Israeli spy Eli Cohen is hanged in Damascus, Syria.
1969 – Apollo program: Apollo 10 is launched.
1980 – Mount St. Helens erupts in Washington, United States, killing 57 people and causing $3 billion in damage.
1990 – In France, a modified TGV train achieves a new rail world speed record of 320.2 mph.
2005 – A second photo from the Hubble Space Telescope confirms that Pluto has two additional moons, Nix and Hydra.
Births

1048 – Omar Khayyám, Persian mathematician, astronomer, and poet (d. 1131)
1822 – Mathew Brady, American photographer and journalist (d. 1896)
1868 – Nicholas II of Russia (d. 1918)
1872 – Bertrand Russell, British mathematician, historian, and philosopher, Nobel Prize laureate (d. 1970)
1883 – Walter Gropius, German-American architect, designed the John F. Kennedy Federal Building (d. 1969)
1904 – Jacob K. Javits, American colonel and politician, 58th New York Attorney General (d. 1986)
1946 – Reggie Jackson, American baseball player
Deaths
1780 – Charles Hardy, English-American admiral and politician, 29th Colonial Governor of New York (b. 1714)
1911 – Gustav Mahler, Austrian composer and conductor (b. 1860)
1980 – Victims of Mount St. Helens eruption. 57 people died

Edited from various sources including historyorb.com, the NYTimes.com Wikipedia and other internet searches