Which event was marked by protests that resulted in police officer deaths in 1886?

The Haymarket Affair, which occurred in 1886, is marked by tragic protests that culminated in violence and the deaths of police officers. This event took place in Chicago during a labor rally advocating for workers’ rights, particularly the eight-hour workday. The atmosphere became increasingly tense, and on May 4, a bomb was thrown at police officers attempting to disperse the crowd. The explosion and subsequent gunfire resulted in the deaths of several police officers and civilians.

This incident has had lasting significance in labor history, as it brought national attention to the labor movement and the struggles faced by workers. It also led to a backlash against labor organizations and a period of hostility towards labor activism in the United States. The Haymarket Affair is often remembered as a pivotal moment that highlighted the challenges of labor relations and the fight for workers' rights during this period.