1926: Joseph Stalin becomes dictator of the Soviet Union. His reign of terror will last for twenty-seven years.

1991: On December 17, President Mikhail Gorbachev orders the dissolution of the Soviet Union, and a new Commonwealth of Independent States is formed by the countries that formerly made up the Soviet Union.

1926: The Theory of the Gene by Columbia University zoologist Thomas Hunt Morgan lays the groundwork for future genetic research.

1984: Veterinarian Steven Willadsen divides sheep embryos and, as a result, clones a sheep.

1926: Don Juan, starring John Barrymore becomes the first film to be accompanied by electrically recorded sound. This process, called Vitaphone, is created by Western Electric.

1980: Videocassettes recorders are a hot item for American consumers. As a result, the rental and sale of videocassettes generate a profitable industry.