- Albert Einstein published his special theory of relativity. (1905) The revolutionary theory was first published in "Annalen der Physik," a major physics journal. The theory immediately rocked the scientific community, and is said to be the basis of modern physics.
- President Truman relieved General MacArthur of his command. (1951) Though MacArthur was a major force in the army in both World War II and Korea, he repeatedly ignored or stretched Truman's orders. The conflict between the two became very public, and Truman eventually replaced him.
- Napoleon was exiled to Elba. (1814) The former emperor abdicated his throne on this day and was sent the island of Elba. He didn't stay there for long, however; a year later Napoleon escaped from Elba, only to be defeated at the Battle of Waterloo some months later and re-exiled.
- Iowa imposed the first state cigarette tax. (1921) Though the US had federal taxes on tobacco on and off since the Civil War, Iowa was the first state to authorize a state-wide cigarette tax. The tax was about $0.02 US Dollars (USD) a pack, which was fairly significant since even the premium brands of cigarettes only cost about $0.25 USD a pack in the 1920s.
- Abraham Lincoln made his last public speech. (1865) Lincoln's last speech centered on promoting the rights of African-Americans. After hearing it, John Wilkes Booth, who had originally been planning to kidnap Lincoln, was so angry that he decided to assassinate him instead.
- Allied forces liberated prisoners at Buchenwald. (1945) More than 200,000 people were imprisoned at Buchenwald during the war, including famous holocaust survivor Elie Wiesel.
- The Civil Rights Act of 1968 was signed. (1968) President Lyndon Johnson signed the act into law on this day as a follow up to the Civil Rights Act of 1964. The act dealt specifically with racial segregation in housing, an issue that the 1964 act did not address.
- Prisoners in the Southern Ohio Correctional Facility rioted. (1993) The riot was one of the longest in prison history, lasting for about 11 days, and was led by an unlikely combination of Sunni Muslims, Aryan Brotherhood members, and Gangster Disciples, an African-American gang.
- The last sentence of death for witchcraft was passed in Germany. (1775) Witchcraft remained punishable by death in many countries around the world throughout the 18th century, though Germany and Switzerland were among the last two European countries to sentence suspected witches to death. By the 21st century, the only country where witchcraft was still punishable by death was Saudi Arabia.
- Idi Amin was overthrown. (1979) Amin was a notoriously unstable and genocidal ruler, and ruled Uganda for eight years before being overthrown by a combination of Tanzanian and Ugandan forces. He is thought to have been responsible for the death of at least 300,000 Ugandans.