The biggest, bloodiest battle ever fought on Texas soil took place in a sandy valley in Atascosa County near the Medina River in 1813, twenty-three years before the battles of the Alamo, Goliad, and San Jacinto. Estimates of up to 1,000 American and Mexican republicans were killed or executed in the last major encounter of Spanish forces in Texas. Spaniards called it the battle of "El Encinal de Medina." In American history it is known as the Gutierrez-Magee Expedition or as the "First Texas Revolution." The gruesome battle halted and destroyed the American filibustering expedition that had...