The History Channel
• On Dec. 16, 1811, the greatest series of earthquakes in U.S. history begins in the Mississippi River Valley near New Madrid, Mo., when a quake of an estimated 8.6 magnitude slams the region. The earthquake raised and lowered parts of the Mississippi Valley by as much as 15 feet and changed the course of the Mississippi River.
• On Dec. 10, 1915, the one-millionth Ford car rolls off the assembly line at the River Rouge plant in Detroit. Between 1908 and 1927, Ford sold more than 15 million Model Ts in all; they initially cost $850 (about $20,000 in today's dollars).
• On Dec. 11, 1946, the United Nations votes to establish the United Nations International Children's Emergency Fund (UNICEF) to provide relief and support to children. Only two countries have failed to ratify the treaty - Somalia and the United States.
• On Dec. 15, 1973, Sandy Hawley becomes the first jockey to win 500 races in a single year. Hawley achieved his historic win aboard Charlie Jr., in the third race at Maryland's Laurel Park race track.
• On Dec. 12, 1989, hotel magnate Leona Helmsley receives a four-year prison sentence, 750 hours of community service and a $7.1 million tax fraud fine in New York.