12 April History
- 1204 - The Fourth Crusade sacks Constantinople.
- 1606 - England adopts the Union Jack as its flag.
- 1770 - Parliament repeals the Townsend Acts.
- 1782 - The British navy wins its only naval engagement against the colonists in the American Revolution at the Battle of Saints, off Dominica.
- 1811 - The first colonists arrive at Cape Disappointment, Washington.
- 1861 - Fort Sumter is shelled by Confederacy, starting America's Civil War.
- 1864 - Confederate Gen. Nathan Bedford Forrest captures Fort Pillow, in Tennessee.
- 1877 - The first catcher's mask is used in a baseball game.
- 1911 - Pierre Prier completes the first non-stop London-Paris flight in three hours and 56 minutes.
- 1916 - American cavalrymen and Mexican bandit troops clash at Parrel, Mexico.
- 1927 - The British Cabinet comes out in favor of voting rights for women.
- 1944 - The U.S. Twentieth Air Force is activated to begin the strategic bombing of Japan.
- 1945 - President Franklin D. Roosevelt dies at Warm Spring, Georgia. Harry S. Truman becomes president.
- 1954 - Bill Haley records "Rock Around the Clock."
- 1955 - Dr. Jonas Salk's discovery of a polio vaccine is announced.
- 1961 - Soviet Yuri Alexeyevich Gagarin becomes first man to orbit the Earth.
- 1963 - Police use dogs and cattle prods on peaceful civil rights demonstrators in Birmingham, Alabama.
- 1966 - Emmett Ashford becomes the first African-American major league umpire.
- 1983 - Harold Washington is elected the first black mayor of Chicago.
12 April Birthdays
- 1777 - Henry Clay, the "Great Compromiser", American politician and statesman who ran unsuccessfully for president three times.
- 1791 - Francis Preston Blair, Washington Globe newspaper editor.
- 1838 - John Shaw Billings, American librarian, army physician.
- 1949 - Scott Turow, writer and attorney.