The Ludlow Massacre in 1914 on this site brought congressional attention to miners' labor rights in Colorado.

(LOWELL, MASS.) On a spring morning in 1914, miners in Ludlow, Colorado, were celebrating Greek Easter when the Colorado National Guard and a private security agency opened fire on their camp with a machine-gun-equipped armored car called the Death Special.

The miners waged a pitched battle with the National Guard for 10 days before President Woodrow Wilson ordered federal soldiers to intervene. An estimated 69 to 199 people were killed. It was the end of one of the most bitter and violent miner strikes in U.S. labor history, which had begun in September 1913. The strike and massacre prompted Congress to take a hard look at labor reform. But significant changes in labor relations and unionization didn’t come until the mid-1930s.

Originally published on theconversation.com, part of the BLOX Digital Content Exchange.