February 9 – Mae West and W. C. Fields join comedic forces for My Little Chickadee with tremendous success. The film becomes one of the highest-grossing of the year.
April 12 – Opening day at Jamaica Racetrack features the use of pari-mutuel betting equipment, a departure from bookmaking heretofore used exclusively throughout New York state. Other NY tracks follow suit later in 1940.
Women's stockings made of nylon are first placed on sale across the U.S. Almost five million pairs are bought on this day.[1]
May 16 – U.S. President Franklin D. Roosevelt, addressing a joint session of Congress, asks for an extraordinary credit of approximately $900 million to finance construction of at least 50,000 airplanes per year.
May 18 – The 6.9 MwEl Centro earthquake affects California's Imperial Valley with a maximum Mercalli intensity of X (Extreme), causing nine deaths and twenty injuries. Financial losses are around $6 million. Significant damage also occurs in Mexicali, Mexico.
July 25 – WWII: President Roosevelt announces a ban on Japan acquiring high-octane aviation fuel from the United States. A ban is also placed on some grades of steel and scrap iron along with some lubricants being banned.[2]
September 2 – WWII: An agreement between America and Great Britain is announced to the effect that 50 U.S. destroyers needed for escort work will be transferred to Great Britain. In return, America gains 99-year leases on British bases in the North Atlantic, West Indies and Bermuda.
September 26 – WWII: The United States imposes a total embargo on all scrap metal shipments to Japan.
October–December
October 1 – The first section of the Pennsylvania Turnpike, the country's first long-distance controlled-access highway, is opened between Irwin and Carlisle.
October 8 – The Cincinnati Reds defeat the Detroit Tigers, 4 games to 3, to win their second World Series championship in baseball.
October 16 – The draft registration of approximately 16 million men begins in the United States.
November 7 – In Tacoma, Washington, the Tacoma Narrows Bridge (nicknamed the "Galloping Gertie") collapses in a 42-mile-per-hour (68 km/h) wind storm, causing the center span of the bridge to sway. When it collapses, a 600-foot-long (180 m) design of the center span falls 190 feet above the water, killing Tubby, a black male cocker spaniel dog.
November 13 – Walt Disney's third feature film, Fantasia, is released. It is the first box office failure for Disney, though it recoups its cost years later and becomes one of the most highly regarded of Disney's films.
December 17 – President Franklin D. Roosevelt, at his regular press conference, first sets forth the outline of his plan to send aid to Great Britain that will become known as Lend-Lease.
December 20 – 1940 New Hampshire earthquakes: A 5.3 Mw earthquake shakes New England with a maximum Mercalli intensity of VII (Very strong). This first event in a doublet earthquake is followed four days later by a 5.6 Mw shock, but total damage from the events is light.
^Trossarelli, L. (2010). "The history of nylon". Club Alpino Italiano, Centro Studi Materiali e Tecniche. Retrieved 2012-02-28.
^Record, Jeffrey (February 1, 2009). "Japanese Aggression and U.S. Policy Responses, 1937-41". JAPAN’S DECISION FOR WAR IN 1941: SOME ENDURING LESSONS. Strategic Studies Institute & United States Army War College. p. 15 – via JSTOR. On July 25 Roosevelt announced a ban on Japanese acquisition of U.S. high-octane aviation gasoline, certain grades of steel and scrap iron, and scrap iron, and some lubricants.