A Mongol horde led by Batu Khan conquered and sacked the Russian city of Ryazan.
Source
John Wayne Gacy was arrested.
French scientists Pierre and Marie Curie discovered radium.
The first manned Moon voyage, the Apollo 8, launched with Frank Borman, Jim Lovell, and William Anders.
The first full-length animated feature film, 'Snow White and the Seven Dwarfs,' premiered.
President Coolidge signed a bill authorizing The Boulder Canyon Project Act, which allowed for the construction of what is known today as the Hoover Dam.
