It just struck me that Leadbelly claims that John Henry had two women. Mary Magdalene and Polly Anne, which interestingly fits with the idea that his wife had to catch a train to get to where he died, and also that she was nearby to cradle his head when he collapsed. In his introduction to the song calls Henry a double drivin' man, but maybe that's double jivin' referring to his women?
Anyways I have found this a fascinating read and read both this page and the original this afternoon. (No mean feat)