Draft animals were the most important piece of farm capital and motive power for transportation in the Great Plains in the premechanization period. These work animals–principally horses, oxen, and mules–were used initially to pull wagons to the Plains and then to pull plows and other farm equipment once the settlers arrived.
Many factors came into play when deciding which type of draft animal to use for the westward trek. Oxen were used most often because they were relatively inexpensive to purchase and could be easily sold or used for food at the final destination, thus serving as a "store of value" for the family's wealth. This final attribute was important because an enormous amount of a family's total wealth, in many cases up to 50 percent, was tied up in the value of the draft animals. If on the trek west a horse broke its leg, an extremely large proportion of a family's wealth would be lost. However, if an ox broke its leg much of the value could be salvaged in the form of meat, either for personal consumption or through sale.
Once at the final destination oxen were then used to plow the prairie sod. This task was one where the ox had a distinct advantage over both the horse and the mule because of its greater strength and torque power. However, after the sod had been turned settlers usually sold or consumed their oxen. From that point on they relied on either horses or mules for their motive power. Both of these animals were better suited to the daily farming chores of the Great Plains, but because horses were less costly than mules they were overwhelmingly preferred on Plains family farms. The more expensive and more resilient mule tended to be used on farms where there were large numbers of hired hands who had less incentive to care for the owner's work stock.
Oxen were used predominately in the early years of Plains settlement, comprising about one-third of all draft animals in 1860. Their numbers declined rapidly thereafter, and they accounted for only about 3 percent of Plains draft animals by 1890. Horses took their place, increasing from 59 percent of all draft animals in 1860 to 89 percent in 1890. The number of mules remained consistently small, varying from 7 to 10 percent between 1860 and 1890. In the early years of the twentieth century, the internal combustion engine signaled the end of the draft animal era on the Plains, though horses are still used extensively in modern-day ranching.
Kyle D. Kauffman Wellesley College
Kauffman, Kyle D. "Why Was the Mule Used in Southern Agriculture? Empirical Evidence of Principal-Agent Solutions." Explorations in Economic History 30 (1993): 336-51.
Kaufman, Kyle D., and Jonathan J. Liebowitz. "Draft Animals on the United States Frontier." Overland Journal 15 (1997): 13-26.