Which incident in 1886 hurt the reputation of unions due to violent acts during a protest?

The Haymarket Affair in 1886 significantly impacted the perception of labor unions due to the violent events that unfolded during a peaceful protest in Chicago. The incident began as a rally in support of workers striking for an eight-hour workday. On May 4, during the gathering, someone threw a bomb at the police, resulting in the death of several officers and civilians. The violence and the subsequent police crackdown led to widespread public fear and backlash against labor movements.

This event was pivotal because it not only resulted in the deaths of individuals but also led to a major trial and the execution of several anarchists, which further fueled a negative narrative around unions and their associations with violence. As a result, the Haymarket Affair caused many to view labor unions as radical and dangerous, detracting from their legitimate goals and grievances. Over time, this incident had long-lasting effects on the labor movement, contributing to a more significant struggle for workers' rights in the United States.