Deering Twine Binder Trade Card, "The Way the Boys Do It in Minnesota & Dakota," 1881

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