Gaines County, on the southern High Plains of West Texas, is bordered on the west by New Mexico. The county was named for James Gaines, a merchant who signed the Texas Declaration of Independence. Sandy loam and sandy soils lie over the county's red-clay subsoil and support a growth of mesquite, shinnery, and catclaw. Cedar Lake (called Laguna Salinas by the Spanish), in northeastern Gaines County, is the largest salt lake on the Texas plains.

The agricultural components of the local economy earn much momey annually from cotton (Gaines County ranks second among cotton-producing counties in Texas), sorghums, vegetables, peanuts, sunflowers, peaches, pecans, cattle, sheep, and hogs. Irrigated land amounts to about 400,000 acres. Gaines County is also one of the state's leading oil counties; it produced 42,810,261 barrels in 1990.

The area was Comanche country until the United States Army campaigns of 1875 and 1876. An Indian burial mound has been excavated near Cedar Lake. It is believed that Quanah Parker, the last great Comanche chief, was born in the vicinity. Cedar Lake was also the site of a skirmish between Indians and United States cavalrymen in October 1875.

Buffalo hunters moved into the region in the 1870s, and some of them began ranches and remained in the area after their game had disappeared. In 1876 the Texas legislature formed Gaines County from Bexar County. Gaines County was attached to Bexar County for administrative purposes in 1876, then to Shackelford County in 1877 and to Martin County in 1885.

As early as 1879 ranchman C. C. Slaughter ran herds on much of eastern Gaines County from his headquarters at Rattlesnake Canyon. C. C. Meddin, who moved his family and herd to Gaines County in 1880, was the first permanent settler. In the 1880s and 1890s other ranchers moved into the area, including C. M. Breckon, the Brunson brothers, Bill Anderson, Dave Ernest, Robinson and Winfield Scott of the Hat Ranch, C. Bill Higgins of the Wishbone Ranch, J. E. Millhollon of the MH Ranch, and the several owners of the Triangle H Triangle north of Seminole. Until the early twentieth century cattle raising was the only industry in the county.

Farming began to develop in the county after 1904, thanks to the sale of railroad land and the 1895 School Land Act, which gave settlers the right to purchase one section of agricultural land at two dollars an acre and three sections of grassland at one dollar an acre. Although mesquite was not as widespread then as now, farmers had to clear shinnery and mesquite from the land before planting.

As more people were moving into the area, the county was formally organized in 1905, with the new town of Seminole designated as the county seat. A courthouse was built in the town in 1906 and a jail in 1907. By 1910, 206 farms and ranches, encompassing 500,772 acres, had been established in Gaines County. About 2,700 acres was planted in corn, the area's most important crop at that time, and farmers had planted more than 2,000 fruit trees (mostly peach). Ranching still dominated the local economy, however.

Rail transportation was delayed until the Santa Fe reached Seagraves in 1917. Until then, food had to be hauled by wagon seventy miles from Midland, and cattle had to be driven to Midland or Amarillo and shipped from there by rail. In spite of the county's new rail connection, however, an extended drought in 1917 and 1918 drove out some of the earlier settlers.

Farming took hold during the 1920s, primarily because of a sudden boom in cotton culture in the area. Only 8 acres in Gaines County was planted in cotton in 1910, and only 485 as late as 1920. By 1929, however, 20,566 acres of the county was devoted to the crop. At the same time, sorghum and corn culture also rose significantly, to 56,500 acres by 1929. The number of farms in Gaines County rose quickly during the 1920s, particularly during the first half of the decade. Meanwhile, cattle ranching continued at a significant level, though declining in its actual and relative importance to the local economy.

Many local farmers were devastated during the 1930s as they suffered through the effects of the Dust Bowl and the Great Depression. Many left their farms to look elsewhere for better economic opportunities. The landscape presented a dismal sight, as sand mounds twenty to thirty feet high and thirty to fifty feet wide were formed by winds that drove vegetation against fences and piled up sand drifts on it. Such sand mounds often surrounded fields that had lost their topsoil to expose a surface of unproductive, hard red clay. Cotton production dropped significantly during the 1930s, and by 1940 only 5,580 acres in the county was devoted to growing the crop.

Some of the worst effects of the Dust Bowl and the depression, however, were offset by the discovery of oil during the 1930s. Drillers first sought oil in the county in 1912 near Cedar Lake, then tried there again in 1918–19 without success. In 1926 the Humble Oil Company leased more than 100,000 acres in the western part of the county at fifty cents an acre. Farmers took this lease bounty with wonder and gratitude. Leasing continued between 1927 and 1929, and prices rose in some places to ten dollars an acre. Actual oil production was not achieved in the county until 1935. In 1936 drillers found the Seminole Pool at 5,000 to 6,000 feet. Other discoveries followed, and in 1938 more than 650,109 barrels of crude was taken from county wells.

The 1940s also saw a revival of agriculture sparked by new irrigation techniques. Farmers abandoned the flood method of irrigation because the sandy soil would not hold the water, and began utilizing the vast stores of underground water with sprinkler irrigation. Mechanization also helped turn what had been a desolate area into a blooming garden. Tractors and other machinery displaced the old technique of plowing one row at a time behind a team of horses.

By the mid-1970s Gaines County had 1,093 cotton farms, 1,023 feed-grain farms, 162 wheat farms, 121 peanut farms, and other farms that grew peaches, pecans, potatoes, beans, and other crops. In 1982 the county ranked first in the state in cotton production with 186,112 bales, fourth in peanuts with 23,895,785 pounds, and sixth in alfalfa production with 23,642 tons. There were also 32,878 cattle and 645 acres of orchards. Irrigated land amounted to 400,000 acres.

Oil production has continued to play an important role in the county's economy. In 1948 crude production totaled more than 15,663,000 barrels and in 1956, more than 24,395,000 barrels. By the 1970s there were seventeen oilfields scattered over the county, with 1,600 wells producing at from 5,000 to 14,000 feet. Production was almost 60,707,000 barrels in 1978 and about 47,522,000 barrels in 1982. The county produced almost 42,686,000 barrels in 1990. By January 1991, 1,670,602,104 barrels of petroleum had been taken from Gaines County since 1936.

A settlement of Mennonites has developed near Seminole. The community has its own school and church and maintains its agrarian religious traditions. Most of the Mennonite farmers moved to Texas from Mexico, where regulations against foreign ownership of land had become burdensome.

The county has a total area of 1,503 square miles, of which 1,502 square miles is land and 1 square mile (0.03%) is water. The population recorded in the 1880 Federal Census was 8. The 2010 census recorded 17,526 residents there.

Neighboring counties are Yoakum County (north), Terry County (north), Dawson County (east), Martin County (southeast), Andrews County (south), and Lea County, New Mexico (west). The county seat is Seminole. Other communities in the county include Denver City, Loop, Seagraves.

Birth Records - The Texas Department of State Health Services has records from 1903 to present. Records for the last 75 years considered private and will only be provided to certain individuals. To obtain current information on who may obtain a record, how to submit a request and an official request form, see the Texas Department of State Health Services website or write to Texas Vital Records, Department of State Health Services, P.O. Box 12040, Austin, TX 78711-2040.

For older birth records you will have to write to the County Clerk of the applicable county. The existence of birth records prior to 1903 will vary widely from county to county. Local historical societies and genealogy collections in local libraries may be able to provide some information.

Death Records - The Texas Department of State Health Services has records from 1903 to present. Records for the last 25 years considered private and will only be provided to certain individuals. To obtain current information on who may obtain a record, how to submit a request and an official request form, see the Texas Department of State Health Services website or write to Texas Vital Records, Department of State Health Services, P.O. Box 12040, Austin, TX 78711-2040.

Marriage Records - The Texas Department of State Health Services can provide a verification letter of marriage for Texas marriages from 1966 to present. This is NOT a marriage license. To obtain a certified copy of a marriage license you must contact the County or District Clerk in the county or district where the marriage took place.

Local historical societies and genealogy collections in local libraries may be able to provide some information.

Divorce Records - The Texas Department of State Health Services can provide a verification letter of divorce for Texas divorces from 1968 to present. This is NOT a copy of the divorce decree. To obtain a certified copy of a copy of the divorce decree you must contact the County or District Clerk in the county or district where the divorce took place.

Local historical societies and genealogy collections in local libraries may be able to provide some information.