On April 21, 1856, Australian stonemasons in Victoria undertook a mass stoppage as part of the eight-hour workday movement. It became a yearly commemoration, inspiring American workers to have their first stoppage. May 1st was chosen to be International Workers’ Day to commemorate the 1886 Haymarket affair in Chicago. In that year beginning on May 1st, there was a general strike for the eight-hour workday. On May 4th, the police acted to disperse a public assembly in support of the strike when an unidentified person threw a bomb. The police responded by firing on the workers. The event led to the deaths of seven police officers and at least thirty-eight civilians; sixty police officers were injured, as were one hundred and fifteen civilians. Hundreds of labor leaders and sympathizers were later rounded-up and four were executed by hanging, after a trial that was seen as a miscarriage of justice. The following day on May 5th, in Milwaukee, Wisconsin, the state militia fired on a crowd of strikers killing seven, including a schoolboy and a man feeding chickens in his yard.