A monument at the Ludlow Tent Colony Site, designated a National Historic Landmark in 2009, stands off Interstate 25 about 25 miles south of Walsenburg.
It commemorates the Ludlow Massacre of 1914, in which Colorado National Guard troops attacked a tent colony of striking coal miners and their families. Two women and 11 children were asphyxiated and burned to death. Three union leaders and two strikers were killed by gunfire, along with one child, one passer-by, and one National Guardsman.
Afterward, miners attacked dozens of mines, leading to the Colorado Coalfield War, the most violent labor conflict in U.S. history with a death toll estimated at 69 to 199. Mary Harris Jones, known as “Mother Jones,” supported the miners during the deadly 1913-14 strike.
The massacre represented a turning point in American labor relations. A Congressional investigation led to passage of child labor laws and a federal mandate for an eight-hour workday.