Coldspring is at the junction of State Highway 150 and Farm roads 1514, 946, and 2025, sixty-five miles north of Houston in central San Jacinto County. According to local tradition, the settlement was named by Joseph Graves for the cold springwater found there. The first post office, named Coonskin, was opened in 1847. Within a year the office was renamed Fireman's Hill, and in 1850 the name was changed to Cold Spring, officially respelled Coldspring in 1894. The town, located on the Robert Rankin grant, became the county seat of newly established San Jacinto County in 1870. County government, agriculture, and lumbering provided the chief sources of income for Coldspring residents during the late nineteenth and early twentieth centuries. The courthouse burned in 1915, and the townsite was moved to its present, more elevated, site. The old town is now marked only by the old San Jacinto County Jail, which was placed on the National Register of Historic Places in 1980 and became a registered Texas landmark in 1982. The first bank in Coldspring opened in 1907, at which time the community had between 400 and 500 residents.
In 1926 the Delta Land and Timber Company built a commissary at Coldspring, which continued to rely heavily on the lumber industry. Five years later the company's sawmill plant was sold to the Kurth interests of Lufkin. A Civilian Conservation Corps camp for black youths operated at Coldspring from the early 1930s to 1937 and somewhat eased the devastating effects of the Great Depression for many local residents. Despite economic problems, the Gulf States Utility Company completed an electrical power line from Shepherd to Coldspring in 1936. In 1945 the Cold Springs oilfield was discovered southeast of town. The construction of Livingston Dam on the Trinity River in 1968 led to further development in the county. Coldspring residents voted to incorporate their city in 1969 by a 114-to-10 margin. Although additional exploratory drilling intensified during the late 1970s, the population of the county seat had declined from an estimated high of 750 in the early 1960s to 675 in 1970 and to 569 in 1980. Much of that decline was apparently due to shifts within the county itself, as seen in the growth of Shepherd, Camilla, and a variety of residential subdivisions. Despite the population trends, the number of rated businesses, which fell from twenty-five in 1960 to eighteen in 1971, had risen to twenty-nine by 1983. The weekly San Jacinto Times has served county residents since 1876. The population was 538 in 1990 and 691 in 2000.