Martin Luther King's Letter from Birmingham Jail is published. King used the open letter to defend his nonviolent resistance against racism and segregation. It became one of the central texts for the civil rights movement in the United States.

Marilyn Monroe performs her famous rendition of Happy Birthday. Monroe gave her sultry performance, which was to be her last, at a party for U.S. President John F. Kennedy. The two are believed to have been engaged in an affair.

The North Vietnamese Army begins organizing the Ho Chi Minh trail. According to the U.S. National Security Agency (NSA), the system of supply routes used by the “Vietcong” was “one of the greatest achievements of military engineering of the 20th century.”

Mustafa Kemal Atatürk sets off the Turkish War of Independence. The fight against the allies of the Triple Entente ended some four years later. The Republic of Turkey was founded, and Atatürk became its first President.

Jean-Pierre Christin invents the Celsius thermometer. The centigrade temperature scale, which is based on the freezing and boiling point of water, is used by most countries around the world. Exceptions include the United State, Belize, and Palau.