John writes: "It is sometimes argued that John Henry's contest could not have occurred as late as 1887-88 (when the RR in Alabama was under construction) because by then steam drills, which were tested extensively just after the Civil War at Hoosac Tunnel (MA), would have been perfected to the extent that no human steel driver could win a contest."

An excellent point. Another is that a contest of the JH sort would hardly depend on any "novelty" in the steam drill. As long as the drill's capability was not self-evidently superhuman, such a contest in earnest or as merely as a challenge would always be possible.