The port at Superior, Wisc. on Lake Superior. Iron ore is taken aboard a freighter. A ship leaves the port. In Gary, the iron ore is made into steel, which is used for building or manufacturing products like automobiles. A man at work in a car plant in Detroit.Other men at work in the plant, attaching doors, putting together engines, attaching tires, painting, sealing glass. Trucks leave the assembly line and are loaded onto a tractor-trailer.