This article examines the choice of draft animal in Southern agriculture in the late nineteenth century and early twentieth century and shows that the preference for the mule over the horse reflected the South's geography. The mule was well suited to the crops that dominated the region. The long, hot summers favored the heat-tolerant mule. The region's geography made it difficult to produce good pastures and encouraged mule breeding to locate at considerable distances from Southern farms. The consequent variation in the price of mules relative to the price of horses across the South shaped the choice of work stock. Also important were the forms of labor organization on Southern farms. This research shows that the choice of the mule over the horse represented an important and progressive step for Southern agriculture.