The Incident

Wages were cut by 2550% at the Pullman Co. In 1894, workers joined American Railway Union and soon struck. After stalled negotiations, ARU supported the strikers by boycotting Pullman cars.
The strike quickly developed into a nationwide railroad strike involving 150,000 workers.
Federal government claimed the mail was being obstructed by the strike. A federal injunction soon prohibited any obstruction or incitement to interference with the railroad business. The injunction was widely flouted. President Cleveland ordered in Federal troops over the protests of Gov. Altgeld of Illinois.