1803 - The United States purchases the Louisiana Territory from France for $15 million, doubling the size of the country.
1908 - The Great White Fleet, a fleet of 16 battleships, leaves Hampton Roads, Virginia, on a world cruise to demonstrate the United States' naval power.
1933 - Adolf Hitler is appointed Chancellor of Germany, beginning the Nazi regime.
1945 - Adolf Hitler commits suicide in his Berlin bunker as Allied forces close in on the city.
1975 - The Vietnam War ends with the fall of Saigon to North Vietnamese forces.
1980 - Queen Juliana of the Netherlands abdicates in favor of her daughter, Beatrix.
1992 - The Los Angeles riots begin after four white police officers are acquitted of the beating of Rodney King, an African-American man.
2011 - Osama bin Laden, the leader of al-Qaeda, is killed by U.S. Navy SEALs in a raid on his compound in Abbottabad, Pakistan.