October 31st

2011
Day of Seven Billion. The world's official population reached 7 billion on approximately this day. The United Nations Population Fund designated it as the Day of Seven Billion.
Day of Seven Billion
1999
EgyptAir Flight 990 crash. EgyptAir Flight 990 crashed off the Eastern coast of the US, killing all 217 people aboard.
EgyptAir Flight 990
1992
Catholic church regrets its handling of Galileo Galilee's case. Then Pope John Paul II acknowledged the errors committed by the Catholic Church while dealing with Galileo Galilei in the 17th century.
Galileo affair
1984
Indira Gandhi assassinated. Indira Gandhi, the first female prime minister of India, was assassinated by two of her bodyguards. Her death sparked riots in India and New Delhi, where several thousand Sikhs were killed.
Assassination of Indira Gandhi
1978
South Yemen adopts constitution. The short-lived People's Democratic Republic of Yemen, or South Yemen, adopted its constitution. South Yemen eventually unified with North Yemen in 1990 to create what is today called Yemen
South Yemen
1956
Rear Admiral G. J. Dufek became the first person to land an airplane at the South Pole.
George J. Dufek
1941
Work on the Mount Rushmore monument was completed.
Mount Rushmore
1918
Spanish flu-virus kills 21,000 in US in 1 week.
1918 flu pandemic
1917
World War I: Battle of Beersheba in southern Palestine - "last successful cavalry charge in history" performed by the 4th Australian Light Horse.
Battle of Beersheba (1917)
1876
Great Backerganj Cyclone of 1876 ravages British India (Modern-day Bangladesh), over 200,000 killed.
1876 Bangladesh cyclone
1864
Nevada became the 36th state.
History of Nevada
1846
A heavy snowfall trapped the Donner Party in the Sierra Nevada mountains.
Donner Party
1541
Michelangelo Buonarroti finishes painting "The Last Judgement" in the Sistine Chapel, Vatican City.
The Last Judgment (Michelangelo)
1517
Martin Luther posted the 95 Theses on the door of the Wittenberg Palace church, marking the start of the Protestant Reformation in Germany.
All Saints' Church, Wittenberg