Born with a hammer in his hand, John Henry was destined to become a steel-driving legend. As a young man, he makes his mark on the American railroads, whistling while he works. But one day, a shady salesman comes to the railroad camp, claiming that his hammering machine is superior to any railroad worker. John Henry steps up to challenge the man's machine, hoping to save the jobs of thousands of railroad workers. But will John Henry be able to prove that a machine can't do what a man can?
