Just finished "Dynamite! A History of Class Violence." A little dry in the first half, but the second half was so good I read it in a day. It was written in '31, but as far as I could tell it's still solid as a rock. There's some dispute over the Molly Maguires in the first chapter, but that's it. I kept wiki-ing, because so much of it is un-fucking-believable.
@dedbees if anyone can recommend a book that can pick up on labor from 30s to now, that'd be great.