Wood County is in northeastern Texas between Interstate highways 20 and 30. Quitman, the county seat, is eighty miles east of Dallas and thirty miles north of Tyler. The county's center is at 32°5' north latitude and 95°0' west longitude. Wood County comprises 689 square miles of the East Texas timberlands with an elevation of 250 to 600 feet above sea level. The western and central parts of the county, in the Post Oak Savannah vegetation area, produce post oak and blackjack oak and tall grasses, and the eastern portion, in the Piney Woods vegetation area, has softwoods such as loblolly, shortleaf, longleaf, and slash pine and hardwoods such as oak, hickory, and maple. The Sabine River drains the southern part of Wood County and forms its southern boundary, and a tributary of the river, Lake Fork Creek, drains the central portion of the county. Coffee Creek drains the northwestern part of the county before it empties into Lake Fork Creek. Big Sandy Creek drains eastern Wood County, and one of its tributaries, Indian Creek, drains the northeastern part. The west has level to undulating terrain with sandy surfaces over clayey subsoils. Central Wood County has gently rolling to hilly terrain and reddish soils with loamy surfaces over very deep clayey subsoils. Eastern Wood County is nearly level and has soils with sandy to loamy surfaces over very deep subsoils. Mineral resources include oil, natural gas, sand, gravel, and clays. The climate is subtropical, moist and mild. The average annual temperature is 64° F. Temperatures in January range from an average low of 32° F to an average high of 54° and in July from 71° to 95° F. The average annual precipitation measures forty-three inches, and the growing season averages 246 days a year.
Caddo Indians lived in the East Texas timberlands centuries before the first Europeans entered the area. The area of Wood County was first explored in 1788 when Pedro Vial made his way from Natchitoches, Louisiana, to San Antonio. Several Spanish land grants were issued for land in the county, but they are relatively unimportant since the county was not extensively settled until after the Texas Revolution. One of the first white men to settle permanently in Wood County was Martin Varner, who lived southeast of the site of present Hainesville by 1824. Webster, the first real community in the area, was established by 1845. In 1850 Wood County was demarked from Van Zandt County and organized. Quitman was established to serve as the county seat. The county was named for George T. Wood, governor of Texas from 1847 to 1849. In 1870 the new Rains County took a section of western Wood County. Wood County was predominantly settled by people who came from the southern United States. These settlers brought slaves with them and began to reestablish the kind of slaveholding, cotton-plantation society they had known in their former homes. In 1850 Wood County had seventeen slaves. By 1860 it had a white population of 3,963 and 923 slaves (roughly 20 percent of the total population) and produced 1,108 bales of cotton. The coming of secession and the Civil War showed the mixed feelings that many citizens of Wood County had toward both subjects. In 1861 the county voted in favor of secession by a majority of 70 percent, yet the two men elected by the county to serve as its delegates to the Secession Convention, John D. Rains and A. P. Shuford, both voted against the secession ordinance. Emory Rains, state senator from Wood County, was one of the signers of the public address asking the citizens of Texas to vote against secession. After the Civil War began Wood County supported the Confederacy with men and material goods. Defeat brought military government and Reconstruction to the county. Reconstruction was effectively ended in 1873 with the election of men from the Democratic party on both the county and state level.
Wood County remained during the years 1870 to 1920 as it was during the antebellum years, overwhelmingly agricultural and rural. During these fifty years both the population and the number of farms grew—from 6,894 and 756, respectively, to all-time highs of 27,707 and 4,333. During those years corn and cotton were the main crops. In 1920 the county produced 1,033,231 bushels of corn, an all-time high. The valuation of county farms stood at almost $19 million. Finally, the percentage of African Americans in the total population gradually decreased during these years to 14 percent, the same percentage as in the 1980s. Wood County enjoyed the benefits of railroad transportation facilities during the period from 1870 to 1920, but even with this advantage, its nonagricultural economy grew slowly. In 1920 there were only twenty-five manufacturing establishments in the county, and they employed 108 people. Even so, the railroads did bring growth. In 1873 the Texas and Pacific Railway came through southern Wood County on its way from Longview to Dallas. A junction was formed with the International and Great Northern Railroad at a tiny village named Sodom, which had about twenty residents. Sodom was renamed Mineola and by the 1990s had a population of 4,321, a municipal water system, a telephone exchange, and a privately owned power plant. Mineola was also the site of one of the largest box and basket factories in the South. The East Line and Red River Railroad came through Winnsboro, in northeastern Wood County, in 1876 as the tracks were being laid from Jefferson to Greenville. The town grew from a population of 333 in 1880 to 2,184 in 1920.
The years of the Great Depression and World War II started long-term changes in Wood County. The county's population began declining, dropping from 24,183 in 1930 to 17,653 in 1960 before the trend began to reverse itself. The number of farms also began to decline; there were almost 3,000 fewer farms in 1959 than there were in 1920. Unemployment became a problem during the depression years. In 1930 only 2 percent of the people could not find work. In 1935 the county had 1,022 workers on public relief. By 1940 unemployment had reached 13 percent of the county's work force. A Civilian Conservation Corps camp was established near Winnsboro during the early 1930s. The discovery of oil in 1941 in Wood County was one of several developments that promised a brighter future. By 1948 the county was producing nearly 25 million barrels of oil a year and by 1984 had produced a total of nearly one billion barrels. The automobile transformed the county. In 1922 the county had forty-nine miles of paved road and 1,000 registered automobiles. By 1982 there were 1,155 miles of paved road and 24,719 registered vehicles. In 1938 the Rural Electrification Administration and the Wood County Electric Coop began bringing electricity to the county's rural areas. Telephone service, starting in 1955 with the Peoples Telephone Coop, was brought into the rural areas. The educational level of the county's citizens also improved. In 1950, 15 percent of those people age twenty-five years or older were high school graduates. By 1980, however, over 50 percent met this standard. By the 1970s the population began to increase again, growing from 18,589 in 1970 to 24,697 in 1980. The county moved from an agricultural base dependent on farming to one that relied on beef and dairy cattle. The nonagricultural economy became more important, with manufacturing, retail trade, and service concerns accounting for 2,102 jobs in 1970 and 3,104 in 1982.
Wood County has supported the Democratic party and politically conservative policies in most of the years since Reconstruction. Citizens voted solidly Democratic until 1956, when the county was carried by Republican Dwight D. Eisenhower. Republicans also won in 1972, 1980, 1984, 1988, and 1992. In 1990 Wood County had a population of 29,380. The 1980s offered the prospect of a relatively stable lifestyle in Wood County, as the oil and cattle industries were being supplemented by tourism and light-scale manufacturing. As of 2014, 42,852 people lived in the county. About 83.7 percent were Anglo, 4.9 percent African American, and 9.3 percent Hispanic. Major communities include Quitman (population, 1,883), the county seat; Mineola (4,721); Winnsboro (3,458, partly in Franklin County); and Holly Lake Ranch (2,973). The annual Dogwood Festival and Old Settlers Reunion in Quitman, along with several recreational lakes, provided ways for the county to attract visitors and new residents.