- US President Ronald Reagan was shot. (1981) Reagan was shot in the chest by John Hinckley Jr., but survived after a two-hour surgery. Hinckley was acquitted on grounds of insanity and committed to a mental institution.
- Anesthesia was used for the first time during surgery. (1842) Doctor Crawford Long administered ether for anesthesia during surgery for the removal of a tumor. He pioneered the use of anesthesia in surgery as well as in childbirth.
- The US purchased Alaska. (1867) In a move known as "Seward's Folly," Secretary of State William H. Seward purchased the land that would later become Alaska from Russia for about $7 million US Dollars (USD). He was mocked throughout the country until gold was discovered in Alaska some 30 years later.
- A Danish prince was elected as the King of Greece. (1863) Prince Vilhelm Georg, also known as George I of Greece was elected by the Greek national assembly after they overthrew the previous king. George was suggested as the next king by several European powers, despite the fact that he was 17 years old at the time of his election.
- The modern pencil was patented. (1858) The first pencil with an attached eraser was patented on this day by Hymen Lipman, who sold the patent four years later for $100,000 USD — an enormous sum at the time.
- Sixth coalition forces captured Paris. (1814) Forces from Russia, Spain, Sweden, the United Kingdom, among other countries, marched in to Paris on this day, effectively ending the main part of the Napoleonic wars. Though Napoleon would continue to fight through the next year, he never regained his full strength after the loss of Paris.
- The 15th Amendment was adopted. (1870) The 15th Amendment was the third in a group dealing with slavery and the rights of African-Americans. It gave African-American men the right to vote, though it would be some years before the amendment was fully implemented in all states.
- Populist farmers rallied to take control of Kansas state government. (1891) The farmers were led by "Sockless" Simpson, an influential Populist leader frustrated by the poor conditions for farmers in the Midwest. Simpson's rally was effective; he was elected to Congress three times, and is thought to have heavily influenced legislation regarding the regulation of railroads as well as fair conditions for farmers.
- Florida territory was created. (1822) The area had been ceded to the US three years earlier, but existed in a sort of limbo until it was organized into a territory. It became a state 23 years later, almost to the day.
- Jeopardy! premiered on TV. (1964) Though most people associate the show with Alex Trebek, Jeopardy! was originally hosted by Art Fleming. The show was actually canceled in 1975, revived in 1978, canceled again in 1979, and only started up again with Trebek in 1984.