In 1929 the Skillet Lickers recorded "Bonaparte's Retreat" in a way easily identifiable as a Bonaparte-y version of "John Henry." In fact, if I hadn't known the title, I'd have thought it *was* "John Henry."

http://www.youtube.com/watch?v=q_vAbEYpQAk

Was some 19th century Southern "BR" the source of the "John Henry" tune?