During the 1913-1914 Colorado coalfield strike, coal miners demanded better wages, an eight-hour work day, a safe workplace, less company control over their lives, and the right to organize. After the United Mine Workers of America called the strike in September 1913, coal companies evicted thousands of miners and their families from company towns, and the union leased land, provided tents, and issued a small allowance. Ludlow became the largest tent colony, with about 200 tents and 1,200 people. A culturally diverse community, made up largely of local Hispanic people and European immigrants speaking at least twenty-four distinct languages, maintained solidarity around a common goal. Violence on both sides plagued the strike. Governor Elias Ammons called out the Colorado National Guard to help keep the peace, but by April 1914 local militia units consisted mostly of company employees who sided against the miners. On April 20, 1914, hostilities reached a climax in the Ludlow Massacre as militia and miners exchanged gunfire, lives were lost on both sides, and the tent colony burned under suspicious circumstances. Two women and eleven children suffocated in a cellar beneath their tent known as the Death Pit, and around 21 people died. The killings outraged the nation and embarrassed John D. Rockefeller Jr., majority owner of the Colorado Fuel and Iron company, and the event helped initiate labor reforms. Rockefeller introduced a plan establishing a company-sponsored union, procedures to air grievances, and improved living conditions in company towns. The Colorado Coalfield War Archaeological Project later investigated the Ludlow Massacre site through excavation and archival research to interpret the events, materials, and lifeways of the Ludlow Tent Colony.