The Haymarket affair occurred on 4 May 1886 when a peaceful rally of striking workers in Chicago, Illinois was interrupted by the police, leading to a group of anarchists throwing a dynamite bomb at the policemen and causing a riot. The workers had been striking for an eight-hour work day and in reaction to the killing of workers the previous day by police, and Samuel Fielden spoke to the crowd for twenty minutes about the alliance between socialism and workers. Police arrived to break the scene up, and a dynamite bomb was thrown at them, killing 7 policemen and 4 civilians; the police forcefully dispersed the protesters in a scuffle that left 70+ protesters wounded and 100+ arrested, while 60+ policemen were injured. Eight anarchists were arrested for the bombing, with four being hanged and one killing himself in prison; the rest were pardoned in 1893. The Haymarket affair led to May Day becoming a day of celebration for workers to commemorate the executed labor activists, and the event led to anti-immigrant sentiment and fear of anarchists rising in the country, as well as increased political consciousness.