| Date | Weekday | Event |
|---|
| July 31, 1498 | Sunday | Christopher Columbus discovers island of Trinidad. |
|
| July 31, 1556 | Tuesday | St. Ignatius of Loyola founder of Society of Jesus died in Rome. |
| July 31, 1588 | Sunday | English fleet attacks Spanish armada |
| July 31, 1777 | Thursday | Marquis de Lafayette 19 made major-general of Continental Army |
| July 31, 1790 | Saturday | 1st US patent granted to Samuel Hopkins for a potash process. |
| July 31, 1813 | Saturday | British invade Plattsburgh NY |
| July 31, 1875 | Saturday | 17th pres Andrew Johnson dies in Tennessee at 66 |
| July 31, 1938 | Sunday | Yanks suspend Jake Powell after he said on Chicago radio 'he'd hit every colored person in Chicago over the head with a club' |
| July 31, 1948 | Saturday | President Truman dedicates Idlewild Field (Kennedy Airport) NY |
| July 31, 1964 | Friday | Ranger 7 transmits the 1st lunar close-up photos before impact |
| July 31, 1964 | Friday | US Ranger 7 takes 4 316 pictures before crashing on moon. |
| July 31, 1970 | Friday | Chet Huntley retires from NBC ending 'Huntley-Brinkley Report' |
| July 31, 1972 | Monday | Democratic VP candidate Thomas Eagleton withdrew |
| July 31, 1977 | Sunday | Son of Sam shot to death 20-year-old Stacy Moskowitz |
| July 31, 1978 | Monday | Yanks now 7 1/2 out of 1st picked up 7 games in previous 2 weeks |
| July 31, 1980 | Thursday | Soyuz 37 crew returns to Earth aboard Soyuz 36 |
| July 31, 1981 | Friday | Leader of Panama Gen. Omar Torrijos killed in a plane crash. |
| July 31, 1981 | Friday | 7-week-old major league baseball strike ended. |
| July 31, 1984 | Tuesday | US men's gymnastics team won team gold medal at LA Summer Olympics |