12th April in history
- 1861 – American Civil War: The war begins with Confederate forces firing on Fort Sumter, in the harbor of Charleston, South Carolina.
- 1862 – American Civil War: The Andrews Raid (the Great Locomotive Chase) occurs, starting from Big Shanty, Georgia (now Kennesaw).
- 1864 – American Civil War: The Battle of Fort Pillow: Confederate forces kill most of the African American soldiers that surrendered at Fort Pillow, Tennessee.
- 1865 – American Civil War: Mobile, Alabama, falls to the Union Army.
- 1877 – The United Kingdom annexes the Transvaal.
- 1910 – SMS Zrínyi, one of the last pre-dreadnought battleships built by the Austro-Hungarian Navy, is launched.
- 1917 – World War I: Canadian forces successfully complete the taking of Vimy Ridge from the Germans.
- 1927 – Shanghai massacre of 1927: Chiang Kai-shek orders the Communist Party of China members executed in Shanghai, ending the First United Front.
- 1927 – Rocksprings, Texas was hit by an F5 tornado that destroyed 235 of the 247 buildings in the town and killed 72 townspeople and injured 205; third deadliest tornado inTexas history.
- 1928 – The Bremen, a German Junkers W 33 type aircraft, takes off for the first successful transatlantic aeroplane flight from east to west.
- 1935 – First flight of the Bristol Blenheim.
- 1937 – Sir Frank Whittle ground-tests the first jet engine designed to power an aircraft, at Rugby, England.
- 1945 – U.S. President Franklin D. Roosevelt dies while in office; Vice President Harry Truman, becomes President upon Roosevelt’s death.
- 1945 – The U.S. Ninth Army under General William H. Simpson crosses the Elbe River astride Magdeburg, and reached Tangermünde—only 50 miles from Berlin.
- 1961 – The Soviet cosmonaut Yuri Gagarin becomes the first human to travel into outer space and perform the first manned orbital flight, Vostok 1.
- 1963 – The Soviet nuclear-powered submarine K-33 collides with the Finnish merchant vessel M/S Finnclipper in the Danish straits.
- 1970 – Soviet submarine K-8, carrying four nuclear torpedoes, sinks in the Bay of Biscay four days after a fire on board.
- 1980 – Samuel Doe takes control of Liberia in a coup d’état, ending over 130 years of minority Americo-Liberian rule over the country.
- 1980 – Terry Fox begins his “Marathon of Hope” at St. John’s, Newfoundland.
- 1981 – The first launch of a Space Shuttle (Columbia) takes place – the STS-1 mission.
Women in Aviation & Defence