"John Henry was a railroad man, / He worked from six 'till five"
~stanza one of an early version of "John Henry, Steel Driving Man"
On the course website, Dr. Jerz asked "In what ways is the John Henry story a tall-tale? How is it social commentary? Is it primarily a story about technology, or about race? Is it too simplistic to say 'both'?"
This story is a tall-tale in the sense that it is exaggerated. John Henry is made out to have superhuman strength. The only argument I can think of that would work against this point is that he dies as a result of using this strength, which I don't think is a trait of these tales, if I recall correctly.
As for how it is a social commentary . . . John Henry tries to prove that he is a better worker than the machine and succeeds in doing so. Technology would still have been new at the point that this came about, so it makes sense that people would have fought against it more than they do now. It is still an issue today, but not as big. Anyways, the social commentary is that humans can be better than machines, despite what people may think.
Going along those same lines, I think it is more about technology than about race. There are race issues involved--more apparent in some versions of the song (and folk lore, most likely) than others--but the main issue seems to be technology.