On this day in labor history, the year was 1877.

That was the day striking railroad workers in Chicago clashed with police in the “Battle of the Halsted Street Viaduct.”

The Great Railroad Strike had reached the nation’s railroad hub, and began there three days earlier.

Switchmen from the Michigan Central traveled to freight shops in yards across the city, calling workers out to strike.

Soon lumbershovers, butchers and industrial workers joined the strike.

By the time the Battle began, police had already clashed with unarmed strikers twice. Historian Richard Schneirov describes the scene leading up to the Battle: “The city was now preparing itself for a full-scale insurrection, even though violent confrontations were rooted in police attacks on non-violent crowds.”

Previous confrontations centered in the railroad yards. Now, strikers’ actions spilled over into the neighborhood of Pilsen, where they lived.

Thousands gathered along Halsted Street between 12th and 16th streets.

The police arrived, attempting to disperse the crowd.

They chased strikers south and as Schneirov describes, “emptied their revolvers into the masses of humanity.”

The crowd pelted the police with stones in defense and chased them over the viaduct.

As word spread of the pitched battle, stockyard workers from nearby Bridgeport walked off the job.

They marched along Halsted Street, with butcher knives in hand, to support the strikers under attack.

The crowd on Halsted swelled to more than 10,000 as workers continued to battle police.

By evening, 30 workers had been shot dead, hundreds more were seriously wounded.

But the strike continued to spread more fiercely.

Streetcar stockmen, stonecutters, gas workers, glasscutters and others joined the strike.

The city was shut down for another week until railroad bosses finally rescinded wage cuts.