Here is a list of things which happened on the 31th of July over the years:
On his third voyage to the Western Hemisphere, Christopher Columbus becomes the first European to discover the island of Trinidad. (1498)
The Spanish Armada is spotted off the coast of England. (1588)
First U.S. patent is issued to inventor Samuel Hopkins for a potash process. (1790)
The NSDAP wins more than 38% of the vote in German elections. (1932)
A doodlebug train in Cuyahoga Falls, Ohio collides with a multi-car freight train heading in the opposite direction, killing 43 people. (1940)
John K. Giles attempts to escape from Alcatraz prison. (1945)
At Idlewild Field in New York, New York International Airport (later renamed John F. Kennedy International Airport) is dedicated. (1948)
Ranger program: Ranger 7 sends back the first close-up photographs of the moon, with images 1,000 times clearer than anything ever seen from earth-bound telescopes. (1964)
Apollo program: Apollo 15 astronauts become the first to ride in a lunar rover. (1971)
Northeast Airlines flies its last flight before being integrated into Delta Air Lines the next day. (1972)
A Delta Air Lines jetliner crashes while landing in fog at Logan Airport, Boston, Massachusetts killing 89. (1973)
The “Son of Sam” killer claimed his last victims when he shot and killed Stacy Moskowitz, 20, and seriously wounded her date as they sat in a parked car in Brooklyn, N.Y. (David Berkowitz was arrested less than two weeks later. He is serving six sentences of 25 years to life.) (1977)
President George H.W. Bush and Soviet President Mikhail S. Gorbachev signed the Strategic Arms Reduction Treaty in Moscow. (1991)
New York City police seized five bombs believed bound for terrorist attacks on subways. (1997)
A bomb exploded inside a cafeteria at the Hebrew University of Jerusalem, killing nine people. (2002)