For most Americans, Labor Day is just a long weekend—but the full history of this holiday tells an darker story, filled with communist violence, mafia corruption, and racial conflict. The Haymarket Affair, a strike-turned-riot in Chicago in 1886, and the controversial trial that followed embodied growing tensions between workers and factory owners. As the American labor movement gained steam in the following decades, unions won some real improvements to working conditions through voluntary negotiation. However, once the federal government got involved, things got more complicated and, unsurprisingly, more corrupt.