- Penicillin was first successfully used to treat a patient. (1942) Anne Miller was suffering from a streptococcal infection, and was nearing death before doctors Orvan Hess and John Bumsfield decided to use an experimental treatment — penicillin. Miller survived, living to be 90 years old, and penicillin became widely used.
- The first recorded town hall meeting took place in America. (1743) The meeting took place in Boston's Faneuil Hall, which still exists. It has been nicknamed the "Cradle of Liberty" because of all the famous speakers it has hosted, including Samuel Adams, Susan B. Anthony, and Oliver Wendell Holmes.
- President John F. Kennedy's body was permanently interred. (1967) The body was originally interred a few feet away from its final resting place in Arlington cemetery, surrounded by a white picket fence with a makeshift torch providing the eternal flame. It was relocated to provide a safer, more permanent arrangement for the eternal flame.
- Gorbachev was elected as the president of the USSR. (1990) Though Gorbachev was popular for instituting a number of reforms in the USSR, he took a lot of criticism for his handling of the election, during which he made repeated threats to resign if he did not receive a majority in the Congress of People's Deputies. He also came under fire for the USSR's faltering economy, and he resigned about a year later.
- The FBI instituted its "Ten Most Wanted Fugitives" list. (1950) Since the list's inception, more than 400 criminals on it have been apprehended, about 100 because of tips from the public. Only seven women have made the list.
- Eli Whitney received a patent for the cotton gin. (1794) The invention of the cotton gin was a first step towards the Industrial Revolution, and greatly influenced the economy of the antebellum American South. Whitney, however, did not make a lot off of his machine due to chronic patent infringements, and he was nearly sent into bankruptcy.
- The Gold Standard Act was ratified. (1900) The act put the US back on a gold standard of currency, after almost half a century of bimetallism, in which money could be exchanged for either silver or gold. Between 1882 and 1933, the US actually issued gold certificates, which could be converted into gold coins at any time.
- The Hay–Herran Treaty was ratified. (1903) The treaty allowed the US to lease the area that now has the Panama Canal, but it was not ratified by the Senate of Colombia, which owned Panama at the time. This led the US to support Panamanian independence both politically and militarily, and eventually to the construction of the Panama Canal.
- Cyprus was sold to Venice. (1489) The Queen of Cyprus, Catherine Cornaro, sold the island to Venice. The island kingdom had been declining for some time because of having to pay heavy tributes to other states, and was eventually controlled entirely by Venetian merchants.
- Albert Einstein was born. (1879) Einstein was named TIME magazine's Person of the Century, and is considered one of the most influential people in the 20th century. He is best known for his theory of relativity, and his less successful unified field theory.