Today:
364 – Valentinian I was proclaimed Roman Emperor by a conference of high-ranking military officers at Nicaea.
1616 – The Roman Catholic Church formally banned Galileo Galilei from teaching or defending the Copernican view that the Earth orbits the Sun.
1815 – Napoleon Bonaparte escaped from his exile on the island of Elba with about 1,000 followers to begin his 100-day re-conquest of France.
1848 – Karl Marx and Friedrich Engels published the Communist Manifesto in London, outlining their theories on class struggle and revolution.
1909 – Kinemacolor, the first successful color motion picture process, was first shown to the general public at the Palace Theatre in London.
1917 – The first jazz record was recorded in New York City by the Original Dixieland Jass Band, who performed the track Livery Stable Blues.
1919 – The United States Congress established the Grand Canyon National Park in Arizona, providing federal protection to the iconic natural landmark.
1935 – Scottish physicist Robert Watson-Watt first demonstrated the use of radio waves to detect aircraft, leading to the development of radar technology.
1952 – Prime Minister Winston Churchill officially announced that Great Britain had developed its own atomic bomb.
1993 – A truck bomb was detonated in the parking garage below the North Tower of the World Trade Center in New York City, killing six people and injuring over 1,000.