Treadmill Operated by Oxen on the Perkins Farm, Bethany, Connecticut, circa 1880

Oxen were the main source of power on many American farms before the development of portable steam and internal combustion engines. Under yoke, they could haul a wide range of heavy objects: logs and boulders; vehicles, like wagons; or agricultural equipment, like plows. Using specially designed treadmills, as shown here, oxen could also power stationary machinery in barns or farmyards.