Haymarket Square Riot of 1886

a demonstration by workers in Chicago that took place May 1, 1886, under the banner of the struggle for an eight-hour workday. It involved participants in a strike by workers of industrial and commercial enterprises that had started that same day and that had totally paralyzed the business life of the city. Demonstrations and mass meetings also took place on the following days. On May 4, during a mass meeting at Haymarket Square, an anti-working class provocation occurred: a bomb thrown into a police detachment killed several policemen and workers. This event brought about the arrest of the workers’ leaders, four of whom were later sentenced to death and were hanged on Nov. 11,1887.

The Haymarket Square Riot of 1886 and the subsequent demonstrations and mass meetings of solidarity with its participants marked the awakening of the political consciousness of the US working class. In memory of the uprising, the Paris congress of the Second International in July 1889 passed a resolution to hold •yearly demonstrations on May 1. In 1890, May Day was celebrated as an international workers’ holiday for the first time.