October 12, 1901
- President of the United States Theodore Roosevelt officially renames the "Executive Mansion" to the White House.
October 13, 1843
- In New York City, Henry Jones and 11 others found B'nai B'rith (the oldest Jewish service organization in the world).
October 13, 1917
- The "Miracle of the Sun" is witnessed by an estimated 70,000 people in the Cova da Iria in Fátima, Portugal.
October 14, 1913
- Senghenydd Colliery Disaster, the United Kingdom's worst coal mining accident, occurs, and it claims the lives of 439 miners.
October 15, 1863
- The H. L. Hunley, the first submarine to sink a ship, sinks during a test, killing its inventor, Horace L. Hunley.
October 15, 1910
- Airship America launched from New Jersey in the first attempt to cross the Atlantic by a powered aircraft.
October 15, 2001
- NASA's Galileo spacecraft passes within 112 miles of Jupiter's moon Io.
October 16, 1793
- Marie Antoinette, wife of Louis XVI, is guillotined at the height of the French Revolution.
October 17, 1604
- German astronomer Johannes Kepler observes a supernova in the constellation Ophiuchus.
October 17, 1933
- Albert Einstein flees Nazi Germany and moves to the United States.
October 18, 320
- Pappus of Alexandria, Greek philosopher, observes an eclipse of the sun and writes a commentary on The Great Astronomer (Almagest).
October 18, 1867
- United States takes possession of Alaska after purchasing it from Russia for $7.2 million.
October 18, 1985
- Super Mario Bros. for the Nintendo Entertainment System is released.
October 19, 439
- The Vandals, led by King Gaiseric, take Carthage in North Africa.
October 19, 1813
- The Battle of Leipzig concludes, giving Napoleon Bonaparte one of his worst defeats.
October 20, 1991
- The Oakland Hills firestorm kills 25 and destroys 3,469 homes and apartments, causing more than $2 billion in damage.
October 21, 1520
- Ferdinand Magellan discovers a strait now known as Strait of Magellan.
October 21, 1965
- Comet Ikeya-Seki approaches perihelion, passing 450,000 kilometers from the sun.
October 22, 1883
- The Metropolitan Opera House in New York City opens with a performance of Gounod's Faust.
October 22, 1964
- A Multi-Party Parliamentary Committee selects the design which becomes the new official Flag of Canada.
October 23, 1086
- At the Battle of Sagrajas, the army of Yusuf ibn Tashfin defeats the forces of Castilian King Alfonso VI.
October 23, 1944
- Battle of Leyte Gulf – The largest naval battle in history begins in the Philippines.
October 24, 1648
- The Peace of Westphalia is signed, marking the end of the Thirty Years' War.
October 24, 1851
- William Lassell discovers the moons Umbriel and Ariel (moon) orbiting Uranus.
October 24, 1929
- "Black Thursday" stock market crash on the New York Stock Exchange.
October 25, 1415
- The army of Henry V of England defeats the French at the Battle of Agincourt.
October 26, 1813
- Canadians and Mohawks defeat the Americans in the Battle of Chateauguay.
October 27, 1810
- United States annexes the former Spanish colony of West Florida.
October 27, 1904
- The first underground New York City Subway line opens; the system becomes the biggest in United States, and one of the biggest in world.
October 27, 1961
- NASA launches the first Saturn I rocket in Mission Saturn-Apollo 1.
October 28, 1636
- A vote of the Great and General Court of the Massachusetts Bay Colony establishes the first college in what would become the United States, today known as Harvard University.
October 28, 1886
- In New York Harbor, President Grover Cleveland dedicates the Statue of Liberty.
October 28, 1919
- The U.S. Congress passes the Volstead Act over President Woodrow Wilson's veto, paving the way for Prohibition to begin the following January.
October 29, 1863
- Eighteen countries meeting in Geneva agree to form the International Red Cross.
October 29, 1888
- The Borki train disaster near Borki station in the former Kharkov Governorate of the Russian Empire (present-day Kharkiv Oblast of Ukraine)
October 30, 1501
- Ballet of Chestnuts – a banquet held by Cesare Borgia in the Papal Palace where fifty prostitutes or courtesans are in attendance for the entertainment of the guests.
October 30, 1974
- The Rumble in the Jungle boxing match between Muhammad Ali and George Foreman takes place in Kinshasa, Zaire.
October 31, 1917
- Battle of Beersheba – "last successful cavalry charge in history".