History of the Day for:
December 21
- 1620: Pilgrims aboard the Mayflower went ashore for the first time at present-day Plymouth, Mass.
- 1898: Scientists Pierre and Marie Curie discovered radium.
- 1909: The first junior high school was established in Berkeley, Calif.
- 1913: The first crossword puzzle was published in the Sunday supplement of the New York World with 32 clues.
- 1914: "Tillie's Punctured Romance," the first six-reel feature-length comedy, made its debut.
- 1929: The first group hospital insurance plan was offered in Dallas.
- 1932: Fred Astaire and Ginger Rogers graced the silver screen together for the first time when "Flying Down to Rio" premiered.
- 1933: Fox signed Shirley Temple, 5, to a studio contract.
- 1937: "Snow White and the Seven Dwarfs," the first feature-length cartoon with color and sound, made its world premiere.
- 1941: Ray McLean of the Chicago Bears made the last NFL drop kick for an extra point.
- 1945: General George S. Patton died in Heidelberg, Germany, of injuries from a car accident.
- 1946: Frank Capra's "It's a Wonderful Life," starring James Stewart and Donna Reed, premiered.
- 1948: The state of Eire (formerly the Irish Free State) declared its independence.
- 1951: Joe DiMaggio announced his retirement.
- 1959: Tom Landry accepted a coaching job with the Dallas Cowboys, which would lead to 22 consecutive winning seasons in 29 years.
- 1968: Apollo 8 was launched from Cape Kennedy with crew Frank Borman, James Lovell, and William Anders. The mission would result in mankind's first orbit of the moon; David Crosby, Stephen Stills and Graham Nash premiered together in California.
- 1969: Diana Ross made her final TV appearance as a member of the Supremes on "The Ed Sullivan Show."
- 1969: Vince Lombardi coached his last football game as his team, the Washington Redskins, lost to the Dallas Cowboys, 20-10.
- 1978: John W. Gacy Jr. was arrested in Des Plaines, Ill. He was eventually convicted of killing 33 men and boys.
- 1983: The NCAA men's basketball rules committee rescinded the last two-minute free throw rule.
- 1988: 270 people were killed when a terrorist bomb exploded aboard a Pan Am Boeing 747 over Lockerbie, Scotland. Efforts to extradite the two suspected bombers from Libya are ongoing.
- 1991: Soviet Union was formally dissolved. Eleven of the twelve republics signed a treaty forming the Commonwealth of Independent States.
- 1992: A Dutch DC-10, flight Martinair MP 495, crashes at Faro Airport (Portugal), killing 56 people.
- 1995: The city of Bethlehem passes from Israeli to Palestinian control.
- 1999: The Spanish Civil Guard intercepts a van loaded with 950 kg of explosives that ETA intended to use to blow up Torre Picasso in Madrid.
- 2007: The Schengen Agreement area increases to include 9 European Union member states; Czech Republic, Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Slovakia, and Slovenia on land and sea borders.