Chicago was the industrial capital of the United States in the late 19th century, and the workers’ union movement was beginning to take root. On Saturday, May 1, 1886, some 35,000 workers walked off their jobs to march in the streets, demanding the instatement of a reduced eight-hour working day. The protestors came to blows with the police, and several workers were killed.
The unions were set on avenging their fellow workers, anarchist groups issued a call to arms, and new demonstrations were organized. The violence came to a head on May 4 during a face-off with the police on Haymarket Square, in the west of the city. An anarchist threw a home-made bomb, and the police opened fire on the protesters.
Three years later in July 1889, European socialist and workers’ parties met in Paris to celebrate the 100th anniversary of the French Revolution. They decided to choose a day to honor the workers’ movement, and picked May 1 in homage to the American strikers killed during the Haymarket riots. This day is now a public holiday in France (where it is known as la fête du Travail) and many other countries all over the world.
The red triangle representing the workers’ demands – eight hours of work, eight hours of leisure and eight hours of sleep – was later replaced by a dog rose, then by a lily of the valley, to symbolize the struggle for workers’ rights. And the tradition has stuck: Today in France it is customary to pick (or buy) a lily of the valley to give to loved ones on May 1.