believe it or not, i first learned about that at the Ludlow memorial , on the side of Interstate 25 just north of Trinidad Colorado.
Coal mining companies are lovely bunch. One of my recent accidental learning is this: https://en.m.wikipedia.org/wiki/Ludlow_Massacre
Discussion
Was it a planned trip there or found it accidentally? Ludlow is something what I didn't want to believe when I read it, this level of exploitation I thought was the past long time. Their sacrifice is our freedom today.