In September 1913, the United Mine Workers of America went on strike against the Colorado Fuel and Iron Company in Colorado seeking better working conditions, enforcement of the eight hour workday law, payment for uncompensated work, the right to choose their own housing, doctors and stores, and enforcement of mine safety rules and state mining laws. Those who went on strike were evicted from their company housing and forced to live in tent villages erected by the union. As tensions rose and confrontations increased, governor Elias Ammons called in the Colorado National Guard.
On the morning of April 20, 1914 the Guard set off two dynamite explosions and began firing a machine gun into the tent village. Gunfire was then exchanged before the Guardsmen stormed the camp and set fire to it, killing nineteen people, including two women, twelve children and five miners. One guardsman was killed.
The strike was called off on December 10, 1914 after the union ran out of money. The strikers’ demands were not met and the union did not gain recognition.