This was the only movie ever blacklisted or banned or whatever. for alleged communist message. Actually, I didn't think it was communist at all, well maybe a little. mainly it was about he standoff between the workers and the mine owners and how a (really ) long strike plays out. The miners are striking for safer conditions, the one dimensional evil capitalist owners are too chinzy to even let them have guys announcing when the blasts are going to be. Alot of people nowadays don't like unions, but if you can get behind any union, it's one where the people are in potential danger, especially underground. You'll be rooting for them and even singing along with their songs "solidarity forever" done to "glory glory hallelueah" and even random chants when thye are saying stuff like "give us the formula, give us the formula" (don't ask). Some of the acting is wooden and I would lke to have seen a little more from the mine owners perspective, but the union leader and his wifes marital difficulties was a good touch and all in all this was very good and quite compelling.
here's a long clip from it