- 1884 - the start of the general strike which eventually won the eight-hour workday in the United States. May 1st, called May Day or Labour Day, is now a holiday recognized in almost every industrialized country; a few exceptions are Canada, the Netherlands, South Africa, and (oddly enough), the United States. It is also a major holiday in the Communist countries.
- 1776 - Adam Weishaupt founds the Illuminati in Ingolstadt, Germany
Holidays and observances:
- Beltane was celebrated by the Celts, and is now celebrated by Neopagans and Wiccans.
- Day of the International Solidarity of Workers (particularly in Communist countries).
- May Day, Labour day - see event section above.