Wikipedia:Selected anniversaries/May 1
On May 1:
- 1776 - Adam Weishaupt founded the Illuminati in Ingolstadt, Germany.
- 1786 - Mozart's opera The Marriage of Figaro premiered in Vienna.
- 1840 - The Penny Black postage stamp was put on sale in the United Kingdom.
- 1884 - May Day: Workers demanded an eight-hour workday in the United States.
- 1893 - The World Columbian Exposition opened in Chicago, Illinois.