This is a subject close to my heart -- thanks Cranky Yankee, wherever you are.
When I first started getting into old folk/blues in earnest, it struck me that the "take" on John Henry I was hearing was usually very different from the one I'd learned in elementary school. To my ears, Mississippi John Hurt's "Spike Driver Blues" or the various versions I know of "Nine Pound Hammer" are NOT about the noble manual laborer being replaced by soulless mechanization. Rather, they're seem to me to be about how shitty manual labor really is. The songs are, if anything, warnings or complaints that if you keep pounding these spikes by hand, you're gunna wind up like John Henry. "Take this hammer and carry it to my captain. Tell him I'm gone."
I think it's spectacularly interesting to see a kind of silent debate over the meaning of the John Henry story. Mostly white-collar, northern folk aficionados (like myself), who can some muster nostalgia for hard labor, just don't think about the story the same way as people like John Hurt, who was probably pretty glad to put down the shovel and get shipped off to New York to do concerts for college kids. This goes to the heart of who the "Folk" really are, who speaks for them, and . . . uh, all that, blah blah, you're bored already.
Oh, and I love what Gillian Welch did with John Henry in that Elvis song.
Kurt "it won't kill me" Gegenhuber