Adolf Hitler, dictator of Nazi Germany who ruled for more than a dozen years, is born in Austria. Hitler's third rift brought World War II and the holocaust that killed 6 million Jews in Europe.

1999:

Two students go on a shooting rampage at Columbine High School in Littleton, Colorado. They kill a dozen classmates and a teacher inside the school before taking their own lives.

1980:

The first Cuban sailing to the United States as part of the massive Mariel boatlift arrive in Florida. Over the next few months, more than 125,000 Cubans reach the U.S. by boat...