2002 – FBI agent Robert Hanssen is sentenced to life imprisonment without the possibility of parole for selling United States secrets to Russia for $1.4 million in cash and diamonds.
1994 – Nelson Mandela is inaugurated as South Africa's first black president.
1981 – François Mitterrand wins the presidential election and becomes the first Socialist President of France in the French Fifth Republic.
1972 – In the Vietnam War, the US had two fighter ace crews. The USAF's Ritchie and DeBellevue scored their first kill while the USN's Cunningham and Driscoll scored their third, fourth and fifth kills.
1962 – Marvel Comics publishes the first issue of The Incredible Hulk.
1960 – The nuclear submarine USS Triton completes Operation Sandblast, the first underwater circumnavigation of the earth.
1954 – Bill Haley & His Comets release "Rock Around the Clock", the first rock and roll record to reach number one on the Billboard charts.
1946 – First successful launch of an American V-2 rocket at White Sands Proving Ground.
1924 – J. Edgar Hoover is appointed first Director of the United States' Federal Bureau of Investigation (FBI), and remains so until his death in 1972.
1922 – The United States annexes the Kingman Reef.
1908 – Mother's Day is observed for the first time in the United States, in Grafton, West Virginia.
1904 – The Horch & Cir. Motorwagenwerke AG is founded. It would eventually become the Audi company.
1872 – Victoria Woodhull becomes the first woman nominated for President of the United States.
1869 – The First Transcontinental Railroad, linking the eastern and western United States, is completed at Promontory Summit, Utah with the golden spike.
1865 – American Civil War: In Kentucky, Union soldiers ambush and mortally wound Confederate raider William Quantrill, who lingers until his death on June 6.
1865 – American Civil War: Jefferson Davis is captured by U.S. troops near Irwinville, Georgia.
1864 – American Civil War: Colonel Emory Upton leads a 10-regiment "Attack-in-depth" assault against the Confederate works at The Battle of Spotsylvania, which, though ultimately unsuccessful, would provide the idea for the massive assault against the Bloody Angle on May 12. Upton is slightly wounded but is immediately promoted to brigadier general.
1857 – Indian Rebellion of 1857: In India, the first war of Independence begins. Sepoys mutiny against their commanding officers at Meerut.
1801 – First Barbary War: The Barbary pirates of Tripoli declare war on the United States of America.
1796 – War of the First Coalition: Napoleon I of France wins a victory against Austrian forces at Lodi bridge over the Adda River in Italy. The Austrians lose some 2,000 men.
1775 – American Revolutionary War: A small Colonial militia led by Ethan Allen and Colonel Benedict Arnold captures Fort Ticonderoga.
1775 – American Revolutionary War: Representatives from the Thirteen Colonies begin the Second Continental Congress in Philadelphia.
1773 – The Parliament of Great Britain passes the Tea Act, designed to save the British East India Company by granting it a monopoly on the North American tea trade.
1497 – Amerigo Vespucci allegedly leaves Cádiz for his first voyage to the New World.
1996 – Tyus Jones, American basketball player
1995 – Missy Franklin, American swimmer
1987 – Wilson Chandler, American basketball player
1978 – Kenan Thompson, American actor
1975 – Adam Deadmarsh, Canadian-American ice hockey player