Jack County, in north central Texas, is bordered by Clay, Archer, and Montague counties to the north, Young County to the west, Palo Pinto and Parker counties to the south, and Wise County to the east. Jacksboro, the county seat and the largest town in the county, is sixty miles southeast of Wichita Falls and seventy miles northwest of Fort Worth. The county's center is at 98°10' west longitude and 33°12' north latitude. Other communities in the county include Bryson, Jermyn, Perrin, Antelope, Wizard Wells, Post Oak, Bartons Chapel, Cundiff, Gibtown, Joplin, Newport (also in Clay County), Truce, and Vineyard. Jack County is situated in the North Central Prairies region. The land is undulating to hilly, with light-colored, loamy soils over very deep reddish clayey subsoils, shale, and sandstone. The county's 920 square miles is forested mainly by mesquite, live oak, blackjack oak, and post oak, with pecan, elm, walnut, and cottonwood trees along the waterways. The altitude increases from east to west and ranges from 800 feet to 1,350 feet. The West Fork of the Trinity River cuts across Jack County diagonally from northwest to southeast and provides the main drainage for the county. Among other creeks are East Rock, Howard, Lost, Crooked, the North Fork of Crooked, Little Cleveland, the West Fork of Keechi, Two Bush, and Henderson. Lake Bridgeport and Lake Jacksboro are in the county. Mineral resources include petroleum, natural gas, and stone. The climate is subtropical-subhumid, generally mild and dry. Temperatures in January range from an average low of 31° F to an average high of 57° and in July from 73° to 97°. The average rainfall is about thirty inches a year, and the growing season extends for 218 days.
Before White settlement Jack County was a borderland between the Caddo Indians to the east and the Comanches to the west. The first Europeans to visit the area may have been Spaniards under Francisco Vásquez de Coronado in the sixteenth century, but they made no permanent settlements. Jack County was included in the Texan Emigration and Land Company, more commonly known as the Peters colony. Settlers began arriving in the future county by 1855, and by 1856 the first settlement, Keechi, was established. Early settlers entering Jack County came mainly from the middle South states, primarily Alabama, North Carolina, Arkansas, Missouri, and Kentucky, many by way of Smith County or other parts of Texas.
The Texas legislature approved the establishment of the county on August 27, 1856, and named it for William H. and Patrick C. Jack, participants in the Texas Revolution. It is the only county with that name in the United States. The Butterfield Overland Mail crossed the county. Fort Richardson, on Lost Creek near the site of present-day Jacksboro, was established by the United States Army in 1867 and completed in 1869. It was the most northern of the Texas frontier forts built to protect pioneers against Indian raids and was abandoned in 1878. Mesquiteville was designated county seat; the town was later renamed Jacksboro.
Because of the county's position on the frontier and its relative isolation, a plantation economy never developed; on the eve of the Civil War only thirty-seven slaves lived in the county. Though the earliest newspaper in the county, the Whiteman (1860), owned and operated by Harris A. Hamner, advocated the Southern cause, county residents voted 76 to 14 against secession in February 1861. The Jack County area was untouched by combat, but the removal of federal troops from the frontier had dire consequences for the populace. Without an army presence, Indian raids became frequent and numerous residents were forced to flee eastward. The 1860 census counted 1,000 people in Jack County, but by 1870 the population had dwindled to 694. Though federal forces returned to the area after the end of the war, Indian raids on the new settlers continued. After the most famous one, the Warren Wagontrain Raid of May 18, 1871, in neighboring Young County, chiefs Satanta and Big Tree were taken to Jacksboro for trial and sentenced to be executed on September 1, 1871. The sentence was commuted to life imprisonment for fear of further Indian uprising.
By the mid-1870s the threat of Indian attack subsided, and during the later half of the decade the county's population rapidly increased. By 1880 the number of residents was 6,629, more than ten times what it had been only a decade before, and by 1890 the population had grown to 9,740. The Chicago, Rock Island and Texas Railway, which reached Jacksboro on August 24, 1898, brought additional growth and provided important access to markets outside the county.
Cattle ranching dominated the county's economy during its early years. The first cattle drive north from Jack County was made in 1866, and by 1890 there were 68,756 cattle in the county. After large-scale farming was introduced in the late 1870s, the number of farms grew rapidly, increasing from 945 in 1880 to 1,888 in 1910. The dominant crop in the county's early years was corn, with 115,761 bushels harvested in 1880 and 663,490 bushels in 1900. During the late 1880s and 1890s oats and wheat were introduced, and by 1920 Jack County was a leading producer of grains; in that year county farmers grew 498,250 bushels of oats, 249,643 bushels of corn, and 351,819 bushels of wheat. Cotton was also grown in considerable quantities after 1890, and by the early 1920s the annual yield was 6,000 bales. Despite the growth of crop farming, livestock raising continued to play an important role in the county's economic life. Revenue from cattle remained an important source of income for many farmers and ranchers, and receipts from poultry and egg production grew throughout the early decades of the twentieth century.
Oil, discovered near Bryson in 1923, set off a small boom, as numerous oilfield workers and others attracted by the prospects of easy money moved in. Nevertheless the population of the county as a whole declined steadily after 1915, largely as the result of a series of agricultural busts. The population, which reached a peak of 11,817 in 1910, fell to 9,863 in 1920 and 9,046 in 1930. Income from oil helped some cash-poor farmers to settle debts and survive the lean years of the Great Depression, but many others were forced to sell their farms and equipment and try their hands at something else. The economy began to recover during World War II, but subsequently the population declined slowly. Between 1940 and 1990 the number of residents fell from 10,206 to 6,981. In the latter year Mexican Americans (3.3 percent) and African Americans (.7 percent) formed the largest minority groups. The largest communities were Jacksboro (3,350) and Bryson (520). In the early 1990s cow and calf operations provided the largest source of agricultural receipts; the leading crop was wheat. The sale of firewood also provided important income. Leading industries included petroleum production and oil-well servicing. Oil production steadily increased to 1,800,000 barrels annually in the early 1990s. Production began to decline thereafter, however. A little over 706,000 barrels of oil and 12,131,871 cubic feet of gas-well gas were produced in the county in 2004; by the end of that year 203,811,409 barrels of oil had been taken from county lands since 1923.
The voters of Jack County favored the Democratic candidate in virtually every presidential election from 1892 through 1948; the only exception occurred in 1928, when Republican Herbert Hoover took the county. After 1952, when Republican Dwight Eisenhower carried the county over Democrat Adlai Stevenson, the area began to trend Republican. Though the Democrats won majorities in the county in 1960, 1964, and 1968, the Republicans took the county in 1972, 1980, 1984, and 1988. Democrat Bill Clinton won a plurality of the county's voters in 1992, at least partly because independent candidate Ross Perot ran strongly in the area during that election. But Republican Bob Dole won a plurality in 1996, and George W. Bush carried the county by large margins in 2000 and 2004. Republican gubernatorial and senatorial candidates also fared well in the late twentieth century, though Democrats continued to occupy many local offices.
Educational facilities in 1990 included a public library in Jacksboro and three public school districts—Jacksboro, Bryson, and Perrin. The educational level of Jack County residents remained relatively constant from 1950 to 1990. In 1950, 29 percent of those attending high school or college received a diploma; by 1960 this percentage had risen to 30 percent. In 1970, 38 percent of the residents of the county had a high school diploma, but the figure had dropped to 30 percent by 1980 and remained stable afterward.
The census counted 8,855 people living in Jack County in 2014. About 78.5 percent were Anglo, 4.2 percent were African American, and 15.8 percent were Hispanic. Almost 76 percent of residents older than age twenty-five had graduated from high school, and almost 13 percent had college degrees. In the early twenty-first century petroleum and gas production, oilfield services, and livestock were the central elements of the area's economy. In 2002 the county had 884 farms and ranches covering 596,172 acres, 72 percent of which were devoted to pasture,19 percent to crops, and 8 percent to woodlands. In that year local farmers and ranchers earned $15,552,000; livestock sales accounted for $14,761,000 of the total. Cattle, hay, wheat, goats, and sheep were the chief agricultural products. Jacksboro (population, 4,565) is the county seat and the county's largest town; other communities include Bryson (526), Perrin (405), and Jermyn (75). Recreational facilities in the county include Fort Richardson State Historical Park, Lake Jacksboro, and Lake Bridgeport. Deer hunting is an important seasonal attraction. Special events include the Jack County Fair in February, the Snake Safari in March, the Weekend in Old Mesquiteville in June, and the Quarterhorse Show in September.