Gainesville, county seat of Cooke County, is in the county's approximate geographic center, on Interstate Highway 35 about sixty-seven miles north of Dallas. In the 1840s the first settlers arrived in the area, attracted by the promises of the newly created Peters colony, which offered 640 acres to each head of family and 320 to each single man, plus land for a church in each settlement. In 1850 Gainesville was established on a 40-acre tract donated by Mary E. Clark. At the suggestion of Col. William F. Fitzhugh, commander of a stockade 3½ miles southeast, the town was named in honor of Gen. Edmund Pendleton Gaines. Gaines, a United States general under whom Fitzhugh had served, had been sympathetic with the Texas Revolution. Gainesville originally consisted of three families who lived in log houses near the banks of Elm Creek. Although Gainesville was made a stop on the Butterfield Overland Mail route in 1858, Indian attacks retarded the community's growth in its first decade. During the Civil War a controversial trial and hanging of suspected Union loyalists brought the new town to the attention of the state (see GREAT HANGING AT GAINESVILLE).
In the decade after the war the county seat had its first period of extended growth, catalyzed by the expansion of the cattle industry in Texas. Gainesville, only seven miles from the Oklahoma border, became a supply point for cowboys driving herds north to Kansas. Within twenty years the population increased from a few hundred to more than 2,000. To the post office, opened in 1851, and the general store were added a number of churches, two banks, a public school, and a weekly newspaper. Gainesville was incorporated on February 17, 1873, and by 1890 was established as a commercial and shipping point for area ranchers and farmers, partly as a result of the arrival in 1886 of the Santa Fe line and the construction in 1887 of the Gainesville, Henrietta and Western Railway. During the 1890s Gainesville College operated for a time, but it was eventually closed, a victim of the depression of 1893 and the consequent rapid decline of the cattle industry.
Unlike some other cattle centers in North Texas, however, Gainesville survived the disappearance of the cattle drives. Its economy continued to grow because of the high price of cotton during the next twenty years. By World War I the county seat had more than 200 businesses and a population of 7,500; in the mid-1930s just under 9,275 people lived in Gainesville. Because oil was discovered nearby in the mid-1920s, the town survived the Great Depression better than similar communities. Also contributing to Gainesville's relative well-being in the 1930s was the success of the Gainesville Community Circus, which first performed in May 1930 and thereafter gained a national reputation. In addition, Camp Howze, an infantry-training center established in the county in 1942, more than doubled the local population and provided much-needed jobs.
After World War II Gainesville's population grew steadily, surpassing 10,000 in the mid-1950s and 14,000 by the late 1980s, when the community reported more than 300 rated businesses. In the 1980s Gainesville residents were served by Cooke County College, the Gainesville Municipal Airport, eight schools, and more than fifty churches. At that time Gainesville was also home to Camp Sweeney, for diabetic children (see SWEENEY, JAMES SHIRLEY), and Gainesville State School for Girls. Businesses at Gainesville included an aircraft firm and a fishing-lure company, and the community also served as a shipping point for sand and gravel. In the early 1990s Gainesville had 600 businesses and a population of 14,587. The population was 15,538 in 2000.