Kingsville, the county seat of Kleberg County, is on U.S. Highway 77 forty miles southwest of Corpus Christi in the north central part of the county. It originated as a town on the St. Louis, Brownsville and Mexico Railway. Around 1900 there was growing sentiment in South Texas for building a railroad to Brownsville. Henrietta King designated a large tract of the King Ranch to be opened for sale, half of which was deeded to a construction company to induce it to build the line. In 1903 Robert Justus Kleberg, manager of the ranch, organized the Kleberg Town and Improvement Company to sell the land for Mrs. King and the railroad-construction company. A surveyor was hired to lay out the townsite three miles east of the headquarters of the King Ranch. The community was named Kingsville, after Richard King. A short time later the tracks reached the site. On July 4, 1904, the first regular passenger train went through the community, and the citizens had a big celebration. A post office was also established in 1904.
After considerable negotiation with the town leaders, railroad officials decided to locate their headquarters in the community, and a general office building and shops were constructed. By the last part of 1906 Kingsville was the home of twenty-five permanent employees of the railroad and their families. The railroad facilities were expanded in subsequent years, and by 1931, 500 persons were working for the railroad and made up one-third of the population of the town. The railroad was the main source of income for Kingsville, and the establishment of the railroad headquarters in Kingsville brought new residents. By 1912 the population was 4,000; in 1930 it had risen to 6,815, of whom 2,000 were Mexican Americans and 524 were African Americans.
Many of the first businesses were established by the King Ranch, which built a hotel, an ice plant, a waterworks, and a cotton gin and started a weekly newspaper. Kingsville became a trade center for farm and ranch families. Many of the farmers ran dairies and sold large quantities of cream to a local creamery. In 1911 the community was incorporated, and a charter was adopted providing for the commission form of city government. In 1913 Kingsville became the county seat of the newly organized Kleberg County. Exploration for oil began shortly after the town was founded, and in 1920 the first producing oil well was discovered nearby. In addition, natural gas was found on a farm southeast of town, and a pipeline was laid to Kingsville that provided gas for residents and businesses. In 1921 residents raised $100,000 to build a cotton mill that employed 175 workers. In 1925 the opening of South Texas Teachers College encouraged more people to come to Kingsville. The college increased its educational scope in 1929, when its name was changed to Texas College of Arts and Industries. In 1993 this institution became Texas A&M University at Kingsville.
Kingsville grew slowly during the 1930s; by 1939 the population was 7,200. The city received a significant stimulus in 1942, when Kingsville Naval Auxiliary Station (later the Naval Air Station, Kingsville) was opened. At one time during World War II personnel at the base numbered between 6,000 and 7,000. In 1944 the Celanese Corporation put in operation its plant five miles north of Kingsville, and most of its employees decided to live in Kingsville. The city suffered a setback when the naval base was closed in 1946, but in 1951 it was reactivated. The new influx of navy personnel stimulated the local economy. In the early 1950s the railroad closed its general office and shops, but Kingsville soon recovered from this reversal. Expansion of the economy continued, and the population rose steadily. The community's growth was due in part to the relocation of the district office of Humble Oil and Refining Company (now Exxon Company, U.S.A.) in Kingsville during the early 1960s. Partly because of the prosperous petroleum industry and the rising enrollment at the college, the population of Kingsville rose from 16,857 in 1950 to 28,711 in 1970. Growth subsequently slowed. A decline in enrollment at the university, the closing of the district office of Exxon in 1985, and the depressed condition of the petroleum industry were the most important factors retarding the city's growth. In 1985 the population of Kingsville was 29,949, and by 1990 the number of residents had fallen to 25,276. The population was 25,575 in 2000.