Final answer:
The phrase "steel-drivin' man" symbolizes John Henry's exceptional physical strength and perseverance, representing human resistance against industrialization's machinery.
Step-by-step explanation:
The phrase "steel-drivin' man" at the end of "John Henry" refers to the legendary figure known for his strength and ability to drive steel drills into rock to make holes for explosives to blast the rock in constructing a railroad tunnel.
This term exemplifies perseverance, physical strength, and the endurance of the human spirit against the encroaching dehumanization of the Industrial Revolution. In the context of the song and the folk hero, John Henry's work represented resistance against the machines that were making manual labor obsolete.