"Unless you’re a southern Coloradan with roots in the area, or a union member well-versed in the hard-fought rights of fellow workers or a history buff who has delved into books on the topic, you could easily not know that in the height of the so-called Progressive Era, the state of Colorado killed scores of strikers at the behest of the world’s richest family. Most U.S. history schoolbooks don’t mention Ludlow. Those that do generally treat it as a blip."