- Dueling was prohibited in Washington D.C. (1839) D.C. had a long history of duels, and even had a "dueling grounds." President Andrew Jackson was involved in several duels, as was Vice President Aaron Burr and Secretary of the Treasury and founding father Alexander Hamilton. The ban came about after Kentucky Representative William Graves killed Maine Representative Jonathan Cilley.
- Ireland allowed the sale of contraceptives. (1985) Until 1979, the sale of contraceptives was banned entirely in Ireland, and after that those who wished to use contraceptives still had to get a prescription to do so. The passage of the 1985 law allowing contraceptives was extremely controversial, and the use of the birth control pill was still banned.
- The US Postal Service was established. (1792) George Washington signed the Postal Service Act on this day, creating the US Postal Service. Although some postal services had run in America before, the USPS was the first and only government-sanctioned postal service.
- The Metropolitan Museum of Art opened. (1872) The famous New York museum has hosted millions of pieces of artwork from a wide variety of periods. Its most famous works on permanent display include its collection of original Tiffany stained glass, Van Gogh's Self Portrait with a Hat and several Stradivarius violins.
- The first American orbited the earth. (1962) John Glenn became the first American to orbit the Earth on this day. The mission had been planned for almost a year in response to the USSR's cosmonaut Yuri Gagarin orbiting the Earth in 1961.
- The Saturday Evening Post published the first of Rockwell's "Four Freedoms." (1943) Norman Rockwell released the paintings to coincide with President Franklin Roosevelt's speech on the Four Freedoms — freedom of speech, freedom of religion, freedom from want, and freedom from fear.
- The Southeast Asian Treaty Organization (SEATO) disbanded. (1976) The organization had consisted of eight countries attempting to "stem the tide of Communism in Asia," but lost its momentum after the Vietnam War. By the time SEATO disbanded, fewer than 200 troops were still carrying out maneuvers.
- Edward O'Hare became the first flying "ace" in World War II. (1942) In order to be considered a flying "ace," a pilot had to have taken down five enemy planes. O'Hare shot down all five of his required planes in less than five minutes, and became the first ace of WWII.
- Congress approved the building of the the San Francisco–Oakland Bay Bridge. (1931) The "Bay Bridge" was an engineering marvel at the time, and had been in the works since the 1840s. It opened six years later, and was immediately jammed with traffic.
- The first woman set foot in Antarctica. (1935) Though the continent had been discovered almost 200 years before, Caroline Mikkelsen became the first woman to reach it on this day. She was part of a Danish expedition along with her husband Captain Klarius Mikkelsen, and a mountain in Antarctica was named in her honor.