Connie,
I am here at the Athens County Historical Society & Museum in the northern section of Appalachian coal country, where coal certainly reigned "king" during the time you describe. From what collections we have, at about that time the men wore cloth caps, similar to painter's caps today, with carbide lamps mounted on the front. Their clothing was not much different than what they would wear out on the street, though they may have had a coverall if they could afford one. The photos I've seen from the time show men and boys with grim determination on their faces, like they know the danger but also know there's no way out of the deals they were in with the companies. Very interesting times.
Jim Sturgill
Executive Director
Athens County Historical Society & Museum