Pope Gregory IV decrees All Saints Day a holy day of obligation for the Catholic religion.

Spanish Franciscan missionaries found the San Juan Capistrano Mission in California.

The ceiling of the Sistine Chapel, painted by Michelangelo, is unveiled to the public.

The first NBA game is played, with the New York Knickerbockers defeating the Toronto Huskies.

Ferdinand Magellan first navigates the Strait of Magellan.

A massive earthquake strikes Lisbon, Portugal, demolishing thousands of buildings and killing over 50,000 people.

United Airlines Flight 629 explodes over Colorado due to a bomb, killing all on board.

John Adams becomes the first U.S. President to reside in the Executive Mansion, later known as the White House.

President Abraham Lincoln appoints George McClellan to replace Winfield Scott as general-in-chief of the Union armies.

Nicholas II becomes the Tsar of Russia following the death of his father, Alexander III.

Italian army lieutenant Giulio Gavotti drops the world's first aerial bomb from a plane over a Turkish camp in Libya.

The Maastricht Treaty officially enters into force, establishing the European Union.

The first issue of The Crisis, a magazine chronicling Black life and the fight for civil rights, is published by W.E.B. Du Bois.

The United States tests 'Ivy Mike,' the world's first thermonuclear bomb, in the Marshall Islands.

Scientists detect evidence of light from the universe's first stars, estimated to have formed 500 million years after the Big Bang.