From 1989 to 1996, Joseph E. B. Elliott photographed Bethlehem Steel, a now defunct site in Pennsylvania that once produced much of the steel in the United States, and is putting out a book with his photos called The Steel: Photographs of the Bethlehem Steel Plant.
PDN has posted some of the amazing photos of this place which I think you should really take a look at. I tried to visit this place once but got sidetracked and ended up passing it by. Last I heard, I think they were building a casino on the land.
If you want to get a glimpse of what it was like to work there, watch this video of a man describing his tenure there.