The other review for this goes off on rants about Fox News (which was not around in 1900 last I checked) and the evils of American capitalism...but the film is about neither. Instead, it's about the state of unrestrained capitalism. In this case, it's set in the United States but could have been almost anywhere back in the day. And, while you could easily and fairly say it's about American capitalism at the turn of the 20th century, these working conditions and practical ownership over the worker do not exist in this country any more and haven't for a very, very long time. So the film is NOT "American Experience" and their attack on an evil country--just an evil time in this country.
The film is set in West Virginia and much of it in southern West Virginia. While the United Mine Workers union was able to establish itself in northern states, in this particular one it wasn't...and the owners of the mines resorted to evil tactics to keep it that way. Hired anti-union armies who took the law into their own hands, governments seemingly bought and paid for my the companies and virtual serfdom for the workers made life unfair and rather hellish. The film is about the efforts of folks like Mother Jones and Frank Kenney to push for the right to unionize and the sad way the state eventually devolved into violence and repression.
The film is reasonably well balanced and informative. It's also important to see because most folks don't even realize that we went through such a period...and such things also occurred in other countries as well due to the notion that capitalism meant property rights for the rich but not everyone else. Fortunately, times have changed and the film makes you thankful of this.