May 4, 1886Primary sourceWell documented
The Haymarket Affair and the Labor Movement
On the timeline · around May 4, 1886 ·
What happened
As American industry boomed, workers organized for shorter hours and better conditions. On May 4, 1886, a rally in Chicago's Haymarket Square in support of the eight-hour workday turned deadly when a bomb was thrown and police opened fire, killing several. In the aftermath, eight labor activists were convicted amid a wave of anti-union hysteria.
Why it matters
Haymarket became a symbol of the era's violent labor conflict and of the long struggle for the eight-hour day and workers' rights. May 1 is commemorated worldwide as International Workers' Day in its memory.