May 1st was chosen to commemorate the 1886 Haymarket affair in Chicago
Happy International Workers' Day!
Dating back to the late nineteenth century, May 1st was chosen to commemorate the 1886 Haymarket affair in Chicago, Illinois, where general strikes and protests took place.
Protesters demanding an eight hour work day for laborers, rather than the sixteen hour day that was commonplace at the time.
The effort to maintain that lifestyle did not seem sustainable to many, so the idea of shortening the work day had been introduced several times before, notably by Karl Marx who questioned the long-term effects on both the workers' health and the overall labor power.
Workers in the US were successful in obtaining an eight hour work day, although it wasn't mandated until 1916. The movement is considered to be one of the most important labor movements in the world - if not the most important one - as other nations followed suit.
The holiday is observed in most countries, though some celebrate it on a different date.
This image inaccurately portrays the Haymarket affair, but is the most reproduced depiction of the events.