Duval County is in south central Texas about fifty miles inland from the Gulf of Mexico and seventy-three miles north of the Rio Grande. It is bordered by Webb, La Salle, McMullen, Live Oak, Jim Wells, Brooks, and Jim Hogg counties. San Diego, the county seat and most populous town, is on the Texas Mexican Railroad at the intersection of State highways 44 and 359 and Farm road 1329, about fifty-two miles west of Corpus Christi and eighty miles east of Laredo. The county's center point is nine miles northwest of Benavides at 27°42' north latitude and 98°30' west longitude. State Highway 44 passes through the county from east to west, and State Highway 16 crosses from north to south. Two highways cross the county diagonally: U.S. Highway 59 and State Highway 359. The county comprises 1,795 square miles of nearly level to undulating terrain with an elevation ranging from 250 to 800 feet above sea level. The northern part of the county drains into the Nueces River, while the central and southern parts drain into the Laguna Madre through Baffin Bay. Northern Duval County is characterized by loamy cracking or crumbly clayey soils, deep to moderately deep, that overlie indurated caliche. Western Duval County is characterized by deep soils with loamy surface layers and loamy or clayey subsoils, and loamy soils with indurated caliche at shallow to moderate depths. Eastern Duval County is characterized by poorly drained loamy soils and well-drained dark soils with loamy surface layers and clayey subsoils. The vegetation consists of small trees, shrubs, and cacti, with large areas of brush. The county's mineral resources include caliche, clay, salt domes, sandstone, uranium, oil, and gas. The climate is subtropical-subhumid. The average minimum temperature is 43° F in January, and the average maximum temperature is 98° in July. The growing season averages 298 days annually. The rainfall averages about twenty-four inches. Less than 1 percent of the land in Duval County is considered prime farmland. Duval County's climate has likely remained unchanged for centuries, but beginning in the late nineteenth century cattle ranching, which was the county's main industry, and farming have had significant effects on the county's vegetation and water supply. Overgrazing led to the destruction of the watershed and clogged the springs that fed the county's streams, most of which are now intermittent, and, in combination with the suppression of grass fires, allowed mesquite to become dominant.
Little is known of the prehistory of the future Duval County. The Venado Indians, a Coahuiltecan hunting and gathering group, roamed the area in the 1700s. The seminomadic Coahuiltecans hunted bison, deer, javelinas, and smaller mammals, as well as snakes, lizards, terrapins, and other reptiles. They also gathered wild fruits, nuts, berries, seeds, roots, leaves, and prickly pear tunas. They were disrupted by the Apache and Comanche incursions from the north and by the Spanish pushing north from Mexico. European exploration of the area apparently began in the eighteenth century, as the road between Mier and Goliad passed through the area. The Marqués de Rubí reportedly crossed the area upon his return from the Spanish frontier in 1767. In 1812 Julián Flores and his son Ventura received the deeds to the San Diego de Arriba and San Diego de Abajo grants, totaling eighty leagues, from the Spanish government; herdsmen in their employ may have been the first European settlers in the county. In 1848 Ventura Flores sold some land on San Diego Creek to Pablo Pérez. The community Perez established there, called Perezville, was the precursor of San Diego. Also in 1848 Henry Lawrence Kinney and William Leslie Cazneau cut a road from Corpus Christi to Laredo that passed through San Diego.
In 1858 the Texas legislature formed Duval County, which originally embraced 1,887 square miles, from parts of Nueces, Live Oak, and Starr counties. County organization did not occur until eighteen years later. The county was named for Burr H. Duval, who fought in the Texas Revolution and was killed in the Goliad Massacre. Duval County has always been somewhat off the beaten track of development. In 1867 Father Claude Jaillet built a church in San Diego that became the only public place of worship between Corpus Christi and the Rio Grande. Despite this civilizing influence, however, Duval County could still be a wild and dangerous place. In 1873 the outlaw Alberto Garza and some sixty followers made the county the center of their horse-stealing and cattle-skinning operations. They sent orders to the citizens of San Diego to bring enough money to buy the stolen hides or enough men to skin the hide-peelers. A party of Anglos chose the latter option, attacked the outlaw's camp, and scattered the rustlers. Five years later, in mid-April 1878, a band of forty Lipan Apache, Seminole, and Kickapoo Indians, reportedly led by a blond White man, cut a swath through Webb and Duval counties, murdering and pillaging several ranches before dispersing. The perpetrators of the so-called "Great Raid of '78" were never caught. A legend of more recent vintage holds that Francisco (Pancho) Villa may have buried two saddlebags of silver in the area. The county was finally organized in 1876, and San Diego was selected as the county seat. James O. Luby, the first county judge, dominated Duval County politics for most of the next three decades. When Luby defected from the Democratic to the Republican party, he almost singlehandedly made the GOP an important factor in Duval County politics. The battles between the Botas and Guaraches ("boots" and "sandals," or Republicans and Democrats) were often ferocious.
Luby was part of an influx of Anglos that also included Walter W. Meek, Sr., who had come to Duval County after the Civil War and helped make it the sheep ranching capital of Texas. The county at the time was described as "one extended pasture" and "a great sheep walk." The Corpus Christi, San Diego and Rio Grande Narrow Gauge Railroad reached the county in 1879, and in 1881, after being taken over by the Texas Mexican Railroad, built across the county and on to Laredo, in Webb County. The arrival of the railroad accelerated the sheep boom. Between 1873 and 1883 Duval County reportedly had more sheep than any other county in the United States. In 1880 county ranchers reported 196,684 sheep, up from 34,325 ten years before; a few years later the county reportedly had more than 400,000. The number of human beings rose with the sheep; in 1880 there were 5,732 people in the county, more than five times as many as in 1870, and Duval County seemed well on its way to lasting prosperity. But in the mid-1880s a mysterious plague began killing the sheep, and after Grover Cleveland was elected president in 1884 on a platform that included eliminating the tariff on foreign wool, the price of wool dropped from twenty-six cents a pound to seven cents a pound. The bottom fell out of the Duval County sheep. There were only 60,160 sheep in the county in 1890 and only 3,627 by 1900.
The White influx led to the county's most enduring characteristic: a vast Mexican-American majority held in thrall by a small but wealthy and influential White minority. In the late nineteenth century Anglos made up less than 10 percent of the county's population but controlled most of the county's trade and politics. Ironically, it was an Anglo, a former cowhand and schoolteacher named Archer Parr, who turned this imbalance to his advantage by soliciting the Mexican Americans, whom his fellow Anglo politicians had traditionally ignored. These people, many of whom were desperately poor, gave up their political autonomy in exchange for county jobs and occasional cash disbursements of questionable legality from the county treasury. This arrangement, which one Duval County official called "frankly corrupt but fully benevolent," allowed Parr, and later his son George B. Parr, a free hand in running the affairs of the county, and became a way of life there. Parr was elected to the Duval County Commissioners Court in 1898, but he did not become the dominant figure in local politics until the assassination of the Duval County Democratic chieftain John Cleary in 1907. By the time Parr was elected to the state Senate in 1914, his control over the affairs of the county was virtually absolute. Yet his power did not go unchallenged. Duval County lost a portion of its land, including the town of Hebbronville, when Jim Hogg County was formed in 1913. Shortly thereafter, Parr made two additional attempts to divide Duval County. Through the establishment of Pat Dunn and Lanham counties he apparently hoped to increase the patronage jobs and tax revenue at his disposal, but he was foiled both times. Between 1912 and 1918 Ed C. Lasater, a wealthy South Texas rancher, and C. W. Robinson, the Duval County Democratic chairman, both attempted to bring Parr down, but neither succeeded. In 1918 D. W. Glasscock, with the support of Governor William P. Hobby and the Texas Rangers, came close to ending Parr's political career. But Parr ultimately prevailed after his fellow senators decided not to examine too closely the irregularities that had characterized Parr's dubious electoral victory over Glasscock.
The Parrs found it expedient to keep the people of Duval County dependent on their largesse, and so placed little emphasis on the state of education in the county. Duval County's 25.3 percent illiteracy rate in 1930 was the sixth highest in the state. Oil was discovered in the county in 1905, but not until a wildcat well came in near Freer in October 1928 did a full-scale oil boom occur. By 1938 Duval County ranked third among the state's 254 counties in oil production, and by 1940 the population of the county reached an all-time high of 20,565. At that time, however, fewer than 7 percent of residents over the age of twenty-five had completed high school. George Parr, the "Duke of Duval," and his cronies became more deeply entrenched than ever, despite his imprisonment in 1936 for tax evasion. Duval County's reputation for political corruption peaked with Lyndon B. Johnson's election to the United States Senate in 1948. The famous Box 13, which gave Johnson his eighty-seven-vote victory, was actually in Jim Wells County, but the manipulation of the returns was almost certainly directed by Parr. In the 1900 presidential election Duval County went Republican, but since that time, thanks largely to the efficiency of the Parr machine and the customary tendency of Hispanics to vote for Democrats, the county has delivered majorities to the Democratic party on the order of 94 percent in 1916, 98 percent in 1932, 95 percent in 1936, 96 percent in 1940, 95 percent in 1944, 97 percent in 1948, and 93 percent in 1964. In fact, only once between 1916 and 1972 did the Democratic candidate receive less than 74 percent of the vote in Duval County; that year, 1956, a mere 68 percent voted Democratic. Even after the demise of the Parr machine in 1975 Democrats continued to dominate. In the 1988 and 1992 presidential elections 82 percent of the county's voters cast ballots for the Democratic candidate.
The oil boom in Duval County did not last. From its peak of 20,289,399 barrels in 1938, production dropped steadily. In 1946 county wells produced only 14,188,268 barrels, fourteenth in the state, and in 1958 the county's 10,167,303 barrels ranked twenty-eighth in Texas. By 1988 Duval County ranked fifty-third in the state, with 3,061,639 barrels. Paralleling the production of oil, the population declined in the second half of the twentieth century. In 1940, at the height of the oil boom, the county population was 20,565. Ten years later it had dropped to 15,643, and in 1960 to 13,398. By 1970 the population was 11,722, and in 1980 it had risen slightly to 12,517, 144th among Texas counties. At least part of the overall decline can be attributed to the problematic nature of the local economy. Farming and ranching in Duval County have never regained the importance they had during the late nineteenth century. That the county lacked the resources to become a major agricultural center was confirmed as far back as 1891 by Professor John T. Ellis of Oberlin College, who in October of that year chose the drought-ridden county as the site for an experimental attempt to produce rain by detonating explosives carried aloft by balloons. Ellis carried out his experiment about a mile and a half northeast of the San Diego railroad station. After several delays because of unsettled weather, a two-day bombardment of the sky apparently paid off with a downpour. But cynics said that Ellis had simply stalled until rain appeared inevitable, and doubts remained about the practicality of the technique.
In the late nineteenth century ranching was Duval County's most important industry. The county's 168 farms in 1880, 165 of which were operated by their owners, had an average size of 2,871 acres, and the county had 6,572 acres of improved farmland; ten years later, after the price of wool had dropped, the number of farms had declined to 102, all but one of which were operated by their owners, with an average size of 2,898 acres; the amount of improved farmland in the county had dropped to 4,331 acres. In the early twentieth century, when farming began to replace ranching as the county's most important agricultural pursuit, the trend was toward more and smaller farms and more tenant farming. In 1910 Duval County had 42,397 acres of improved farmland and 633 farms, 249 of which were operated by tenants, averaging 805 acres. In 1920 the amount of improved farmland rose to 52,232 acres and the number of farms to 754; 324 of these were operated by tenants, but the average size had declined to 584 acres. The trend peaked in 1930, when county farmers harvested 67,473 acres of cropland. In that year tenants operated 843 of the county's 1,241 farms, which averaged 579 acres. By 1950, however, the amount of harvested cropland and the number of farms had dropped to 50,675 acres and 711 respectively, but the average farm had grown to 1,632 acres. In subsequent decades the number of farms again increased, while the average size again decreased. In 1959, for example, there were 716 farms, averaging 1,056 acres; in 1969 there were 825 farms, averaging 1,198 acres; and in 1982 there were 1,074 farms, averaging 904 acres.
Mexican-American ranchers were growing cotton experimentally in Duval County in the 1880s, but by 1900 the county's production totaled only 638 bales. Production climbed to 3,570 bales by 1910 and 7,133 bales by 1920, however, and continued to climb for most of the next decade. In 1930, when 55,943 of the county's 67,473 acres of harvested cropland was devoted to cotton, 11,773 bales of Duval County cotton were ginned. In subsequent years cotton has diminished in importance to the county economy; only 4,159 bales were ginned in 1936, 1,656 in 1945, 1,124 in 1950, and a mere 571 in 1969. With the diminishing importance of cotton, other crops assumed prominence at various times. Duval County produced 351,999 pounds of peanuts in 1959 and 1,142,407 pounds in 1969, but by 1982 the local harvest had declined to insignificance. In 1940 Duval County farmers devoted 16,736 acres to sorghum culture; in 1959 that total had dropped slightly, to 15,701 acres, but by 1982 it had risen to 34,334 acres that yielded 1,447,319 bushels. In 1982, 2,519 acres, the fourth-highest total in the state, was devoted to watermelons, down from 2,778 acres in 1959. The amount of harvested cropland in Duval County declined for several decades, from 65,659 acres in 1940 to 50,675 in 1950 and 39,263 in 1969, but rose to 58,744 in 1982. In 1982 Duval County ranked ninth in the state in the production of peaches, with 9,500 bushels, and third in the state in the production of dry cowpeas and dry southern peas, with 24,460 bushels. The cattle industry had made something of a comeback. Duval County had 20,667 cattle, excluding milk cows, in 1920; in 1940 the total was 49,025, and in the mid-1950s the county was considered one of the state's leading beef producers. In the early 1980s Duval County had 80,795 cattle and calves, including 51,365 beef cows and 1,676 milk cows. The county's $28,372,000 in cash receipts from crops and livestock ranked 135th in the state.
At the peak of manufacturing in 1900 the county had only seven manufacturing establishments that together employed only twenty-eight people, and throughout most of the twentieth century the number of such establishments has ranged between two and six. In 1982 only 2 percent of the county's labor force was employed in manufacturing and the county had only three manufacturing establishments, each employing fewer than twenty people.
In 1982, 86 percent of Duval County's estimated population of 12,900 were of Hispanic origin, the eighth-highest percentage in the United States; 7 percent were of English descent, 5 percent of German descent, and 5 percent of Irish descent. The percentage of those over the age of twenty-five who had graduated from high school rose from 7.6 percent in 1950 to 11.3 percent in 1960 and 36.6 percent in 1980, but the latter figure still lagged well behind the state average of 62.2 percent. Twenty-three percent of the county's workers were employed in other counties, 31 percent in agriculture and mining, 21 percent in professional services, and 14 percent in wholesale or retail trade. Tourists, attracted by such spectacles as Freer's annual Rattlesnake Roundup in April and Old Fiddlers Contest in July, spent $3,519,000 in Duval County in 1982. In 1990 the population was 12,918.
The U.S. Census counted 11,533 people living in Duval County in 2014; about 10 percent were Anglo and 88.5 percent Hispanic. Of those twenty-five and older, 60 percent had graduated from high school and 9 percent had college degrees. In the early twenty-first century ranching, petroleum products and tourism were central elements of the area’s economy. In 2002 the county had 1,228 farms and ranches covering 850,360 acres, 74 percent of which were devoted to pasture, 19 percent to crops, and 5 percent to woodlands. That year farmers and ranchers in the area earned $12,951,000; livestock sales accounted for $11,136,000 of the total. While beef cattle generated most of the area’s agricultural income, dairy products and cotton, vegetable, grains, and hay were also produced in the county. More than 1,365,000 barrels of oil, and 72,169,865 thousand cubic feet of gas well gas, were produced in the county in 2004; by the end of that year 585,742,696 barrels of oil had been taken from county lands since 1905.
The largest communities are San Diego (population 4,417, with 3,247 inhabitants in Duval County and the rest in Jim Wells County) and Freer, with 2,791 residents. Freer holds a rattlesnake roundup in April.