A chart depicting the number of horses, tractors, trucks, and autos on U.S. farms throughout the first half of the 20th century. The number of horses declines dramatically, while the number of tractors, trucks, and autos rises.

Horses and Machinery on Farms (thousands)

Source: Olmstead, Alan L., and Paul W. Rhode. “The Agricultural Mechanization Controversy of the Interwar Years.” Agricultural History 68, no. 3 (1994): 36.Get the dataCreated with Datawrapper