The Haymarket Affair was a labor protest that took place on May 4, 1886, in Chicago's Haymarket Square. It began as a peaceful rally in support of workers striking for an eight-hour workday. The event turned violent when a bomb was thrown at the police, leading to chaos and the deaths of several police officers and civilians. In the aftermath, the authorities arrested and tried several anarchists, blaming them for the violence. The trials were controversial, resulting in the execution of four men and sparking widespread debate about labor rights, free speech, and the treatment of workers in the United States.