High Quality Content by WIKIPEDIA articles! In 1837, the tribe migrated into southwest Texas and northern Mexico, away from encroaching American settlers. Due to their diminishing numbers, they were supervised by the Wichita Agency. In 1858 Tonkawa fought as allies of the Texas Rangers in the Battle of Little Robe Creek. Due to Tonkawa loyalty to the Confederacy during the American Civil War, in 1862 pro-Union tribes fought against them, killing 133 out of the remaining 309 Tonkawa, in what is known as the Tonkawa Massacre