1940
- Memphis Minnie writes a tribute song to Ma Rainey.
- May 15: Jackie Shane is born.
- October 7: Althea Garrison is born.
- October 31: Craig Rodwell is born.
1941
- Willem Arondeus begins an underground periodical as part of the Dutch Resistance.
1943
- Allied forces invade the island of Sicily and store munitions in the Addaura Cave. The munitions explode, revealing previously undiscovered rock art.
- Willem Arondeus joins force with another underground publication in order to increase their circulation.
- March 27: Willem Arondeus leads the bombing of the Amsterdam Public Records Office, in order to hinder Nazi efforts to root out Jews in the area.
- July 1: Willem Arondeus is executed by Nazis. His last message is: “Let it be known that homosexuals are not cowards.”
1945
- Christine Jorgensen — still living as a man — graduates high school and enlists in the Army, serving during the end of World War II.
- Willem Arondeus is awarded a posthumous medal and buried at Erebegraafplaats Bloemendaal.
- Alan Turing begins working on the Automatic Computing Engine (ACE).
- August 24: Marsha P. Johnson is born.
1946
- King George IV awards Alan Turing with the Order of the British Empire — his classified work with codebreaking during World War II is estimated to have saved thousands of lives.
1947
- The Sex Perversion Elimination Program begins in the United States.
1948
- Alfred Kinsey publishes “Sexual Behavior in the Human Male”.
1949
- Herman Weber attempts to restart the Scientific-Humanitarian Committee. This group ultimately becomes the Committee for the Reform of Sexual Criminal Laws.
- March 1: Danny Garvin is born.