Workers are striking in front of the McCormick Harvester Company in Chicago, Illinois. They are trying to get higher wages, better and safer working conditions, and shorter working days. They are also trying to end child labor.
The strikebreakers came to replace the striking workers, and the workers were not happy about it. A large riot broke out between the two groups.
The police came to try and settle down both groups, but they had to use force. They shot into the crowd and four workers were killed.
The next day, thousands of workers gathered in Haymarket Square to protest the killings that happened the day before. This rally was led by anarchists.
A bomb went off and killed seven of the police officers in the square. It was believed that the anarchists planted the bomb.
Eight anarchists were arrested because it was believed that they planted the bombs. Many Americans thought that the unions were controlled by anarchists. Four anarchists were put in jail and the other four were hanged.