Spanish explorers introduced cattle to the New World, and these long-horned ancestors of Geronimo roamed the Texas landscape for 500 years. Shaped by the wild Texas landscape, the longhorn developed toughness, cleverness, and independence that helped it survive harsh conditions and marginal food sources, especially in the Wild Horse Desert. Large Spanish ranches stretched across the lower Rio Grande region, where vaqueros tended cattle from horseback. The breed's tenacity, longevity, sturdy hooves, and ability to travel long distances made it well suited to the epic cattle drives of the late 1800s. During the Civil War, longhorn herds roamed and thrived on the open range, and by the war's end their numbers had reached the millions. In the postwar South, and especially in Texas, financial hardship coincided with opportunity as high demand for beef and stocker cattle on the Midwestern prairies created a major new industry backed by northern bankers and British financiers. Developed entirely by natural selection, the Texas longhorn became the foundation of the cattle industry of the Southwestern United States. Live Oak County lay along the early Chisholm and Western Trails, and from Brownsville to the Oklahoma border wild longhorns were driven to territories across the United States.