- 1955 – The polio vaccine, developed by Dr. Jonas Salk, is declared safe and effective.
- 1961 – The Russian (Soviet) cosmonaut Yuri Gagarin becomes the first human to travel into outer space and perform the first manned orbital flight, in Vostok 3KA-2 (Vostok 1).
- 1992 – The Euro Disney Resort officially opens with its theme park Euro Disneyland. The resort and its park’s name are subsequently changed to Disneyland Paris.
- 1994 – Canter & Siegel post the first commercial mass Usenet spam.