On October 17, 1835, Texans approve a , a corps of armed and mounted lawmen designed to “range and guard the frontier between the Brazos and Trinity Rivers.”
In the midst of their revolt against Mexico, Texan leaders felt they needed a semi-official force of armed men who would defend the isolated frontier settlers of the Lone Star Republic against both Santa Ana’s soldiers and Native Americans; the Texas Rangers filled this role. But after winning their revolutionary war with Mexico the following year, Texans decided to keep the Rangers, both to defend against Native Americans and Mexicans and to serve as the principal law enforcement authority along the sparsely populated Texan frontier.
Although created and sanctioned by the Texas government, the Rangers was an irregular body made up of civilians who furnished their own horses and weapons. Given the vast expanse of territory they patrolled and the difficulty of communicating with the central government, the government gave the men of the Rangers considerable independence to act as they saw fit. Sometimes the Rangers served as a military force, taking on the role of fighting the Native Americans that in the U.S. was largely the responsibility of the Army. At other times the Rangers mainly served as the principal law enforcement power in many frontier regions of Texas, earning lasting fame for their ability to track down and eliminate outlaws, cattle thieves, train robbers and murderers, including such notorious bandits as John Wesley Hardin and King Fisher.
Even as late as the first two decades of the 20th century, the state of Texas continued to rely on the Rangers to enforce order in the wilder regions of the state, like the oil boomtowns along the Rio Grande. Increasingly, though, some Texans began to criticize the Rangers, arguing that they used excessive violence and often failed to observe the finer points of the law when apprehending suspects. As a result, in the 1930s, the state won control over the Rangers, transforming it into a modern law enforcement organization.