31 July History
- 904 - Arabs capture Thessalonica.
- 1703 - English novelist Daniel Defoe is made to stand in the pillory as punishment for offending the government and church with his satire The Shortest Way With Dissenters.
- 1760 - Ferdinand, Duke of Brunswick, drives the French army back to the Rhine River.
- 1790 - The U.S. Patent Office opens.
- 1882 - Belle and Sam Starr are charged with horse stealing in the Indian territory.
- 1875 - Former president Andrew Johnson dies at the age of 66.
- 1891 - Great Britain declares territories in Southern Africa up to the Congo to be within their sphere of influence.
- 1904 - The Trans-Siberian railroad connecting the Ural mountains with Russia's Pacific coast, is completed.
- 1917 - The third Battle of Ypres commences as the British attack the German lines.
- 1932 - Adolf Hitler's Nationalist Socialist German Workers' Party (Nazis) doubles its strength in legislative elections.
- 1944 - The Soviet army takes Kovno, the capital of Lithuania.
- 1971 - Apollo 15 astronauts take a drive on the moon in their land rover.
31 July Birthdays
- 1803 - John Ericsson, naval engineer and inventor, developed the screw propeller.
- 1816 - George Henry Thomas, Union general during the American Civil War.
- 1837 - William Clarke Quantrill, Confederate raider during the American Civil War.
- 1867 - S.S. Kresge, American businessman.
- 1901 - Jean Dubuffet, French sculptor and painter.
- 1912 - Milton Friedman, Nobel Prize-winning economist.
- 1919 - Primo Levi, Italian writer and scientist (Survival in Auschwitz).
- 1921 - Whitney Young, Jr., civil rights leader and executive director of the National Urban League.
- 1928 - Horace Silver, jazz pianist, composer and bandleader.
- 1951 - Evonne Goolagong, Australian tennis player.