Why May 1 is International Workers' Day

May 1, celebrated as International Workers' Day in Italy and most of the world, commemorates the Haymarket Affair in Chicago in 1886, a pivotal moment in the fight for an eight-hour workday. The holiday was declared in 1889 at the Paris congress that founded the Second International. The Haymarket Affair began on May 1, 1886, with a general strike called "The Great Revolt." On May 3, police fired on striking workers at the McCormick reaper factory, killing six. The next day, an anarchist group organized a protest at Haymarket Square. A bomb thrown at police killed seven officers and wounded sixty; police then fired into the crowd, killing three protesters. The bomber was never identified, but eight anarchists were convicted in a flawed trial; four were hanged on November 11, 1887. The event galvanized labor movements globally. In Italy, May 1 also recalls the 1947 Portella della Ginestra massacre, where bandit Salvatore Giuliano fired on a crowd of workers, killing 11 people including two children.