1974: Western Union (in cooperation with NASA and Hughes Aircraft) launches the United States' first commercial geosynchronous communications satellite, Westar 1.
1972: The Universal Postal Union decides to recognize the People's Republic of China as the only legitimate Chinese representative, effectively expelling the Republic of China administering Taiwan.
1970: An oxygen tank aboard Apollo 13 explodes, putting the crew in great danger and causing major damage to the spacecraft while en route to the Moon.
1964: At the Academy Awards, Sidney Poitier becomes the first African-American male to win the Best Actor award for the 1963 film Lilies of the Field.
1960: The United States launches Transit 1-B, the world's first satellite navigation system.
1948: In an ambush, 78 Jewish doctors, nurses and medical students from Hadassah Hospital, and a British soldier, are massacred by Arabs in Sheikh Jarrah.
1945: World War II: Soviet and Bulgarian forces capture Vienna.
1945: World War II: German troops kill more than 1,000 political and military prisoners in Gardelegen, Germany.
1943: World War II: The discovery of mass graves of Polish prisoners of war killed by Soviet forces in the Katyń Forest Massacre is announced, causing a diplomatic rift between the Polish government-in-exile in London from the Soviet Union, which denies responsibility.
1941: A Pact of neutrality between the USSR and Japan is signed.
1919: Eugene V. Debs is imprisoned at the Atlanta Federal Penitentiary in Atlanta, Georgia, for speaking out against the draft during World War I.
1919: Jallianwala Bagh massacre: British troops gun down at least 379 unarmed demonstrators in Amritsar, India; at least 1200 are wounded.