Starr County is in South Texas, bordered by Hidalgo County to the east, Brooks County to the northeast, Jim Hogg County to the north, and Zapata County to the west. The Rio Grande serves as its boundary with Mexico to the south. The county seat is Rio Grande City, which is on U.S. Highway 83 and the Border Pacific Railroad. The center of the county is at 26°34' north latitude and 98°44' west longitude. Starr County is part of the Rio Grande Plain region and comprises 1,226 square miles with elevations from 200 to 400 feet above sea level. The northeastern part of the county has sandy or light-colored and loamy soils over very deep, reddish or mottled clayey subsoils. Soils in the central part of the county are light-colored, deep to moderately deep, and well drained. In the southwest soils are gray to black cracking clay. Limestone can be found within forty inches of the surface. Along the river, brown to red loams cover cracking clayey soils. Starr County is in the South Texas Plains vegetation region, characterized by mid and short grasses, thorny shrubs, mesquite, cacti, and live and post oak. In 1982, 80 percent of the land was in farms and ranches, with 17 percent of the farmland under cultivation and 19 percent irrigated. Less than 1 percent of the land in the county was considered prime farmland. The primary crops were sorghum and hay. Vegetables were also grown, and the county was second in the state for onions, cantaloupes, lettuce, bell peppers, and honeydew melons and fourth for cabbage. Primary fruits were oranges, and the primary livestock was cattle. Natural resources included caliche, clay, and gravel, oil, and gas. Gas and oil production is significant. Starr County has a subtropical, subhumid climate with mild winters and hot summers. Temperatures range from an average minimum of 44° F in January to an average maximum of 99° F in July. The average annual temperature is 74° F. Rainfall averages twenty-two inches a year, and the growing season lasts 305 days.
Evidence indicates that Indians inhabited the region for 11,000 years. During the Archaic Period the inhabitants were hunter-gatherers who did not practise agriculture and had no domesticated animals. Later peoples began experimenting with farming. It is unlikely that Spanish explorers entered the area in the sixteenth century. In August 1638 Jacinto García de Sepulveda followed the Rio Grande, and crossed into the area at Mier in search of Dutch sailors reported on the Texas coast. In 1687 the second expedition of Alonso De León in search of Fort St. Louis also followed the river route. In 1747 Miguel de la Garza Falcón reconnoitered the northern bank of the river in search for suitable land to establish a settlement. He condemned the land as unsuitable for stock raising and farming and deemed it uninhabitable. Despite his complaint the area drew the attention of the Spanish crown, and in 1749 José de Escandón was assigned the task of colonizing the area. As a consequence of the colonization effort two communities were founded south of the Rio Grande across from the future Starr County. Later the settlers in those towns moved across the river. The grantees found the land suitable for cattle and sheep raising and were also successful at settling the area. Ten land grants and seventy-one porciones were issued between 1749 and 1846 by the Spanish and Mexican governments in the northern and northeastern parts of what later became Starr County. Like the rest of the Rio Grande valley, the area's economy was based on cattle and sheep ranching during the Spanish colonial and Mexican periods. The first settlement in the area was made in 1763 by Francisco de la Garza Martinéz, son of Blas María de la Garza Falcón, who was granted porcíon 80 in 1767 by Spain. The villa was named Rancho Carnestolendas. Another early settlement was Corrales de los Saenz, founded about 1763 by the Saenz family. The community fell within porciones 71 and 72, which were issued to Juan Salinas and Juan Ángel Saens, respectively, by Spain in 1767. By 1850 Los Saenz had been renamed Roma-Los Saenz and was a thriving community.
Area residents dedicated their labor to sheep and cattle ranching. The area was disputed after the Texas Revolution, when both Mexico and the Republic of Texas claimed it. In 1847 Henry Clay Davis established the town of Rancho Davis on the Rio Grande near the site of the former Carnestolendas Ranch. After the Treaty of Guadalupe Hidalgo ended the Mexican War in 1848, the area became part of Nueces County. Camp Ringgold, later Fort Ringgold, was established at Rancho Davis on October 26, 1848, the year the county was organized and named for James Harper Starr. Rancho Davis was renamed Rio Grande City and made county seat. The introduction of steamboats on the Rio Grande in the late 1840s made trading centers of Rio Grande City and Roma. After 1849 itinerant Oblates of Mary Immaculate periodically visited the ranches between Brownsville and Laredo. By 1850 the county's population was estimated at 8,541. Starr County lost a large portion of its eastern territory when Hidalgo County was established in 1852, and by 1860 Zapata County had taken part of its western land. That year Starr County had a population estimated at 2,400. However, by 1870 the population had again increased to an estimated 4,154, predominantly Hispanic. In 1860 the county had 4,639 cattle and 19,142 sheep on seventy-one ranches. The county had only 6,628 improved acres, and the only crop reported that year was 2,616 bushels of corn. Settlers in the county during the late 1860s were predominantly Civil War veterans who stayed to make their fortune. They engaged in light trade and smuggling; few purchased land outright. Most chose to marry into established Hispanic ranching families. For the most part the newcomers adopted Hispanic traditions, including becoming Catholic, learning Spanish, and adopting the patronage system.
Machine politics in Starr County came to the forefront during the 1870s and 1880s, when Manuel Guerra, rancher and merchant, asserted control of the county as political boss. Before that, county politics had been dominated by the Anglo minority of ranchers, merchants, and lawyers. Guerra's power over the Reds, as the Democrats were called, however, was not absolute, although he did have the support of James B. Wells, the political boss of South Texas. Guerra's biggest rivals were other Hispanics with political aspirations. Starr County, unlike other lower Rio Grande valley counties, had a proportionately high number of Mexican Americans contending for public office. In 1880 the county population was 8,304, of whom 211 were black. In the 1880s the Casino Club of Rio Grande City was formed. It was a social, literary, nonpolitical organization that also accepted Anglos as members. Other societies included La Unión, Los Mexicanos Tejanos, and the Filopolitas Society, which allowed low-income members. Newspapers in the city during this period included La Voz del Pueblo and the weekly El Alacrán. The Rio Grande City Riot of 1888 focused national attention on Starr County. Despite the growing importance of agriculture, ranching continued to be a profitable enterprise for Starr County residents in the late 1880s. This was exemplified by ranchers such as Felipe Guerra, who reported 25,000 acres of land worth $6,000 and 980 cattle with an estimated value of $4,390. Two other successful ranchers were Luis Martínez, who held 38,318 acres of land valued at $19,309 and 650 livestock worth $4,000, and Sino Martínez, who owned 22,500 acres appraised at $1,600 and 900 cattle worth $7,000. Sheep ranching also continued to be an important industry; by 1890 there were 50,966 sheep in the county. That year the population was estimated at 10,749. As early as 1891 Starr County residents initiated a plan to build an irrigation dam on the Rio Grande north of Rio Grande City.
In 1894 Wells negotiated a truce between Manuel Guerra and Sheriff W. W. Shely, who agreed to share party patronage and party nominations; the truce allowed the Democratic party to reassert its domination over Starr County politics. Guerra was also able to gain a seat on the commissioners' court. By the end of 1900 John R. Moore had been elected county judge by the Blues (see REDS AND BLUES). Starr County again made headlines in November 20, 1899, when black troops of the Ninth United States Cavalry stationed at Fort Ringgold fired on Rio Grande City. The attack lasted long enough for the citizenry to call for aid from the Texas Rangers. The county's population was 11,469 in 1900. Race relations in Starr County during the nineteenth century were amicable even as the number of Anglo-Americans moving to the area increased. As a consequence of the new stream of settlers and the desire of Mexican ranchers to adapt to the new farming economy of the lower Rio Grande valley, Starr County had 382 farms, comprising 1,005,065 acres, by 1900. That year the county had 18,745 cattle and 21,003 sheep. Old settlers ranched along the river and in the south central part of the county, and the new farmers grouped together in the northern area of the county. The most famous of these northern settlers was Edward C. Lasater, who founded Falfurrias in the area that became Brooks County. In 1860 there had only been seventy-one farms in the county, but by 1910 there were 918. In 1900, forty-eight acres of corn and 1,615 acres of cotton were planted. By 1910 cultivation had risen to 14,339 acres of cotton and 2,825 acres of corn. However, crops had not replaced cattle ranching, which peaked that year with 85,425 cattle. Sheep ranching was on the decline; only 8,942 sheep were reported that year.
Brooks County was carved out of northern Starr County in 1911, after a long and bitter feud between the Lasater and Guerra factions. Lassater had agitated for the formation of a county that would free him and other farmers of machine politics. However, Brooks County cost Starr County its best farmland. In 1915 Starr County became a target of border raiders and officials requested help from the adjutant general. Not until the twentieth century, with the advent of irrigation and the railroad to the lower Rio Grande valley, were new Anglo settlers drawn to the area in large numbers. In 1920 the population remained 90 percent Hispanic, in part because the railroad did not reach it until 1925. As more Anglos arrived in the 1920s and 1930s race relations changed in Starr County. The newcomers, unlike their predecessors, remained segregated. The population fell from 13,151 in 1910 to 11,089 in 1920. Thereafter it increased to 11,409 in 1930 and 13,312 in 1940. As part of the wartime search for new sources of rubber, Starr County was chosen for a guayule experiment in 1942. This desert shrub that produces rubber was planted in the county because of its arid climate, and experiments in its cultivation continued after the war. In 1944 Fort Ringgold was permanently closed by the army, and much of the land and several buildings were acquired by the county school district. The buildings were used to house teachers and as junior and senior high schools. The Guerra party had been in trouble since 1936, when Texas Rangers investigated Starr County politics, and was defeated by the "New party" in 1946. Little changed for the county during the 1950s; it remained composed of a dispersed rural Hispanic population. By 1960 Starr County had an estimated population of 17,137. Political scandals reemerged in the 1960s. In 1962 an absentee-voting probe conducted in the county uncovered fraudulent applications for absentee ballots, false notarization of applications, and forged poll-tax rolls. The Guerra machine had regained its power by 1963, when M. A. "Poncho" Guerra assumed control as party leader; the Guerra family had been able to maintain its power through economic control of its constituents. In June 1966 a wildcat strike was led by pickers against eight major Starr County growers. Most of the strikers' activity was aimed at the La Casita Farms Corporation. The Starr County sheriff imported Mexican labor and broke the strike (see STARR COUNTY STRIKE). In the 1960s many of the county's colonias were started.
In 1970 the population was 17,707 and the most important industries were oil and agribusiness. Between 1929 and 1970 oil production totaled more than 216 million barrels. During the early 1970s the average annual farm income was $11 million. Crops, including vegetables, feed crops, and cotton, were concentrated on 35,000 irrigated acres along the Rio Grande. In 1970 the county was again under investigation for voting violations. It was alleged that impoverished individuals were being paid twelve dollars a month for their vote. During the 1970s a grand jury found that as many as 50 percent of the county's citizens were involved in drug smuggling. Starr County was the largest producer of peyote, which was grown and harvested under federal license for sale to Indians, who used it for religious ceremonies. The population was estimated at 27,266 in 1980. In 1985 Starr County residents' per capita income was $2,668 per year; more than 50 percent of the county's residents lived below the poverty level. In January of that year the unemployment rate in the county was 52.2 percent, and the median family income was 42 percent of the national average. The population remained 97 percent Hispanic. In March 1985, 50 percent of the population received food stamps. The extreme poverty was attributed to the lack of jobs in the economically depressed oil industry as well as unemployment in other states, which displaced migrant farmworkers. In 1986 Starr County was one of the poorest counties in the nation. Between 8,000 and 10,000 residents lived in colonias outside Rio Grande City, and another 3,200 in twenty to thirty other colonias spread throughout the rest of the county. Many colonia residents who worked as migrant farmworkers took their children out of school to follow the crops so that the whole family could work. In 1993 Starr County was the nation's second poorest county, with 60 percent of its population living below the poverty rate; it also ranked first in percentage of persons of Spanish origin and forty-first in the highest birthrate. Starr County residents have participated in presidential elections since 1848, when they voted for Lewis Cass. In every election through 1992 residents have voted for the Democratic candidate, except in 1872, 1876, 1880, and 1892. Recreational attractions in Starr County include Las Palomas State Wildlife Management Area, International Falcon Reservoir, and year-round hunting. Special events and festivals include the Starr County Fair and the Fourth of July Parade and Festival, held in Rio Grande City. The county also has a number of fine examples of nineteenth-century border architecture, primarily the work of Heinrich Portscheller. In 2014 Starr County had a population of 62,955. About 3.9 percent were Anglo, 0.4 percent African American, and 95.7 percent Hispanic. The principal communities included Rio Grande City (population, 14,132), Escobares (2,753), La Grulla (1,612), and Roma (9,830).