In 1823, only two years after Anglo-American colonization formally began in Texas, empresario Stephen F. Austin hired ten experienced frontiersmen as "Rangers" for a punitive expedition against a band of Indians. But not until November 24, 1835, did Texas lawmakers institute a specific force known as the Texas Rangers. The organization had a complement of fifty-six men in three companies, each officered by a captain and two lieutenants, whose immediate superior and leader had the rank of major and was subject to the commander-in-chief of the regular army. The major was responsible for enlisting recruits, enforcing rules, and applying discipline. Officers received the same pay as United States dragoons and privates-$1.25 a day; however, they supplied their own mounts, equipment, arms, and rations. At all times they had to be ready to ride, equipped "with a good and sufficient horse...[and] with one hundred rounds of powder and ball."

Even with such official sanctions, the Rangers did not fare especially well at first. During the Texas Revolution they served sparingly as scouts and couriers, then carried out a number of menial tasks. As settlers fled east to escape advancing Mexican armies after the fall of the Alamo on March 6, 1836, the Rangers retrieved cattle, convoyed refugees across muddy trails and swollen streams, and destroyed produce or equipment left behind. In fact, during the battle of San Jacinto on April 21, they were on "escort" duty, much to their chagrin. Nor did their situation improve appreciably over the next two years because President Sam Houston favored government economy as well as friendship with the Indians. In December 1838, however, Mirabeau B. Lamar succeeded to the presidency and immediately changed the frontier policies of the republic as well as the role of the Rangers. At his behest, Congress allowed him to recruit eight companies of mounted volunteers and maintain a company of fifty-six Rangers, then a month later to provide for five similar companies in Central and South Texas. Over the next three years the Rangers waged all-out war against the Indians, successfully participating in numerous pitched battles. The most notable were the Cherokee War in East Texas in July 1839, the Council House Fight at San Antonio against the Comanches in March 1840, and the battle of Plum Creek (near the site of present-day Lockhart) against 1,000 Comanche warriors in August 1840. By the end of the Lamar administration, Texans had undermined, if not broken, the strength of the most powerful tribes. Sam Houston, upon being reelected to the presidency in December 1841, realized that Ranger companies were the least expensive and the most efficient way to protect the frontier. As a result, 150 Rangers under Capt. John Coffee "Jack" Hays figured prominently in helping repel the Mexican invasions of 1842 and in successfully protecting Texans against Indian attacks over the next three years. Hays initiated Ranger traditions and esprit de corps by recruiting and training a tough contingent of men skilled in frontier warfare. Out of his command arose such famous Ranger captains as Ben and Henry McCulloch, Samuel H. Walker, W. A. A. "Big Foot" Wallace, and Robert Addison "Ad" Gillespie .

With annexation and the Mexican War in 1846, the Rangers achieved worldwide fame as a fighting force. After acquitting themselves admirably during the battles of Palo Alto and Resaca de la Palma on May 8–9, 1846, they became Gen. Zachary Taylor's "eyes and ears." Superbly mounted, "armed to the teeth" with a large assortment of weapons, and obviously at home in the desert wastes of northeastern Mexico, they found the "most practical route" for the American army to Monterrey. Late in September the Rangers rashly set the tempo and style for Taylor's successful storming of the city. Although furloughed in October after a brief armistice, they returned early in 1847 in time to provide the general enough military information to help win the battle of Buena Vista in February. In March 1847, the theater of war shifted. An American army under Gen. Winfield Scott landed at Veracruz and quickly muscled its way into the Valley of Mexico. For the next five months the Rangers under Jack Hays and Samuel Walker figured prominently in American victories. In fact, so ruthless and lethal were they against Mexican guerrillas that a hostile but fearful populace called them "los diablos Tejanos."

After the Mexican War ended on February 2, 1848, the Rangers became for the next decade, as historian Walter Prescott Webb asserted, "little more than an historical expression." Since the United States had rightly assumed responsibility for protecting the Texas frontier, the Rangers had no official function. Nor did the state try to enlist their services. The organization thus lost its famous captains as well as the nucleus of its frontier defenders. But after the appointment of John S. "Rip" Ford as senior captain in January 1858 the Rangers briefly upheld their fighting traditions. Late in the spring they moved north of the Red River to "chastise" a large band of "hostiles," in the process killing the noted Comanche chief, Iron Jacket. Then in March 1859 Ford and his men were assigned to the Brownsville area, where, together with the United States Army, they gained only limited success against the "Red Robber of the Rio Grande," Juan N. Cortina. For fourteen years after this campaign, however, the Rangers ceased to be either significant or effective. With the coming of the Civil War in 1861, they rushed individually to the Confederate colors. Although the Eighth Texas Cavalry was known as Terry's Texas Rangers, its founder, Benjamin F. Terry, was never a member of the state organization, nor did he necessarily recruit experienced fighters. To protect its frontiers the state had to rely on young boys, old men, or rejects from Confederate conscription. Subsequently, during Reconstruction (1865–74), either the United States army or the State Police were responsible for carrying out such duties, though they had little success.

But in 1874 the state Democrats returned to power, and so did the Rangers. Texas was "overrun with bad men," with Indians ravaging the western frontier, with Mexican bandits pillaging and murdering along the Rio Grande. The legislature authorized two unique military groups to meet this emergency. The first was the Special Force of Rangers under Capt. Leander H. McNelly. In 1874 he and his men helped curb lawlessness engendered by the deadly Sutton-Taylor Feud in Dewitt County. In the spring of 1875 they moved into the Nueces Strip (between Corpus Christi and the Rio Grande) to combat Cortina's "favorite bravos." After eight months of fighting, the Rangers had largely restored order, if not peace, in the area. In 1875 the Special Force enhanced its fearful reputation by stacking twelve dead rustlers "like cordwood" in the Brownsville square as a lethal response to the death of one Ranger; McNelly also precipitated the "Las Cuevas War," wherein he violated international law by crossing the Rio Grande, attacking Mexican nationals, and retrieving stolen American cattle. The second military unit, designated the Frontier Battalion, was equally effective. Composed of six companies (with seventy-five Rangers in each) under Maj. John B. Jones, the battalion participated in fifteen Indian battles in 1874 and, together with the United States Cavalry, destroyed the power of the fierce Comanches and Kiowas by the end of 1875. The battalion also "thinned out" more than 3,000 Texas desperados such as bank robber Sam Bass and notorious gunfighter John Wesley Hardin; therefore, because of its very efficiency, the Frontier Battalion was no longer necessary after 1882.

For the next three decades the Rangers retreated before the onslaught of civilization, their prominence and prestige waning as the need for frontier law enforcement lessened. They occasionally intercepted Mexican and Indian marauders along the Rio Grande, contended with cattle thieves, especially in the Big Bend country and the Panhandle, and at times protected blacks from white lynch mobs (see LYNCHING). By 1900 such relative inactivity persuaded critics to urge the curtailment, if not complete abandonment, of the Rangers. As a result, in 1901, the legislature cut the force to four companies, each headed by a captain who could recruit no more than twenty men. Only because of the leadership and valor of such captains as J. A. Brooks, William Jesse McDonald, John H. Rogers, and John R. Hughes were the Rangers able to maintain their existence-and traditions-during the lean years of the 1890s and early 1900s.

Violence and brutality soon increased along the Rio Grande, however, where the Rangers continued to participate in numerous bloody brush fights with Mexican nationals. In 1910 a revolution against President Porfirio Díaz unsettled the populace on both sides of the border. In 1914, early in World War I, problems in the border country focused on Mexican nationalism, German intrigue and sabotage, and American draft dodgers. Then in 1916 Pancho (Francisco) Villa's raid on Columbus, New Mexico, intensified already harsh feelings between the two countries. The regular Rangers, along with hundreds of special Rangers appointed by Texas governors, killed approximately 5,000 Hispanics between 1914 and 1919, a source of scandal and embarrassment. In January 1919, at the insistence of Representative José T. Canales of Brownsville, the legislature overhauled the force in order to restore public confidence. During the next two months sordid stories of Ranger brutality and debauchery and injustice emerged. As a result, Texas lawmakers decided to maintain the four companies but reduce the number of recruits from twenty to fifteen per unit. To attract "men of high moral character" they instituted more competitive salaries, but with minimal expense accounts. They also established specific procedures for citizen complaints against any Ranger wrongdoing. After these reforms the force performed well during the 1920s, especially under the leadership of captains William L. Wright, Thomas R. Hickman, and Frank (Francis A.) Hamer. After the enactment of Prohibition the Rangers constantly patrolled the Rio Grande against tequila smugglers and cattle rustlers. They protected federal inspectors from bodily harm in the so-called "tick war" in East Texas, prevented both individual injury and property damage in labor flare-ups or Ku Klux Klan demonstrations, and tamed the lawless oil boomtowns of Miranda City, Desdemona, Mexia, Wink, and Borger.

With the Great Depression (1929-), Ranger fortunes began to ebb. The legislature had to slash the budget, so that during the depression the force complement never exceeded forty-five. As for transportation, the Rangers depended on free railroad passes or their own horses along the border. In the fall of 1932 they made a grave error in judgment: they openly supported Governor Ross Sterling against Miriam A. "Ma" Ferguson in the Democratic primary. In January 1933, upon taking office, Ma fired every Ranger for his partisanship-forty-four in all. The legislature then slashed salaries and budgets and further reduced the force to thirty-two men. Texas consequently became a haven for the lawless-the likes of Raymond Hamilton, George "Machine Gun" Kelly, and Clyde Barrow and Bonnie Parker.

In 1935, however, James Allred became governor on a platform of better law enforcement. The legislature therefore established the Texas Department of Public Safety. A three-person Public Safety Commission was responsible for selecting a director and an assistant director, who, in turn, oversaw three basic units: the Texas Rangers, the Highway Patrol, and a scientific crime laboratory and detection center known as the Headquarters Division. The Rangers therefore became an important part of a much larger law-enforcement team. Their basic five-company structure remained intact, but changes occurred in hiring and promotion procedures. All appointments were now through examinations and recommendations (not by political patronage); each applicant must be between thirty and forty-five, stand at least 5'8", and be "perfectly sound" in mind and body. Upon acceptance, each received instructions in the latest techniques of fingerprinting, communications, ballistics, and records. Each had to be a "crack shot." Although the commission established no educational provisions, each Ranger had to take a written examination and submit an "intelligent" weekly report of his activities. As for promotion, seniority and performance were the all-determining factors.

For several years the Rangers were apprehensive about their future because of leadership changes in the DPS. But late in September 1938, with the appointment of Colonel Homer Garrison, Jr., as the new director, the Rangers regained their high status. Over the next thirty years-the Garrison era-the Rangers became the plainclothesmen of the DPS: they were the detectives, and the Highway Patrol officers were the uniformed state police. The Rangers also expanded to six companies (each with a captain and a sergeant), with an overall complement of forty-five men in 1941, fifty-one in 1947, and sixty-two in 1961. They were actually a rural constabulary, with most of the officers stationed individually in small Texas towns. The governor, however, could assign them to a case anywhere in the state. The Rangers were skilled in using the modern scientific laboratory of the Headquarters Division. During the Garrison era the Rangers operated at peak performance, thereby enhancing their prestige. In World War II, they rounded up enemy aliens and instructed civilians and local police in the latest defense techniques to protect generating plants, dams, factories, and industries from sabotage, while carrying out their regular duties. In the 1950s they investigated more than 8,000 cases annually. And in the 1960s their caseload increased because of the civil-rights movement and the emergence of a more populous, urban state (see URBANIZATION).

When Garrison died in 1968, the DPS commissioners again reorganized and redefined Ranger guidelines. Under Garrison's successor, Col. Wilson E. Speir, the force expanded to seventy-three men in 1969, eighty-two in 1971, eighty-eight in 1974, and ninety-four a year later. The Rangers also were highly trained and better equipped. Recruits had to be between the ages of thirty and fifty, have at least eight years of on-the-job police experience, and have an intermediate certificate signifying 400 to 600 hours of classroom instruction. The DPS provided the Rangers with high-powered cars equipped with the latest radio equipment as well as with a large array of sophisticated weapons and defensive armor. The state also began paying better salaries, together with such benefits as longevity pay, hospitalization insurance, and a paid life-insurance policy. As a result, the Rangers evolved into the elite of Texas law enforcement. During the Garrison era such captains as Manuel T. "Lone Wolf" Gonzaullas, Alfred Y. Allee, Bob Crowder, Johnny Klevenhagen, Eddie Oliver, and Clint Peoples were instrumental in maintaining Ranger tradition and performance. Subsequently, captains Bill Wilson, J. L. "Skippy" Rundell, H. R. "Lefty" Block, and Maurice Cook continued to improve the force. The training was intensified, the weaponry and crime-detection equipment became even more sophisticated, and, despite increasing case loads, the applicant list for Ranger service grew. In recognition of the Rangers' toughness against the criminal element and their dedication to state law enforcement, the legislature enlarged the overall complement to ninety-nine officers (including two women) in September 1993 and again increased salaries and fringe benefits. By September 1996 the force had expanded to 105.