Thorp Spring is on Farm Road 4 five miles northwest of Granbury in north central Hood County. Though Pleasant Thorp settled in the area near the banks of Strouds Creek in the 1850s, Indian attacks slowed community development until the early 1870s. In 1871 Sam Milliken purchased a portion of the old Thorp homestead, built a cotton gin, and established a resort hotel, which advertised the medical benefits of the nearby waters. Two years later, brothers Randolph and Addison Clark opened Add-Ran College (later named Add-Ran Christian University when the school was taken over by the Disciples of Christ in 1890). They transferred its operations to Waco in 1896, and its name eventually changed to Texas Christian University. In 1893 a post office opened in Thorp Spring, and during that decade the population surpassed 400, thereafter continuing to grow, reaching a high of 485 by 1904. Thorp Spring was bypassed by the railroads that crisscrossed the county during the 1890s. In 1910 Thorp Spring Christian College replaced Add-Ran College. The town reported a population of more than 400 until the mid-1960s, when it began a steady decline, and the number of reported businesses decreased from three to none. By 1990 Thorp Spring reported 184 residents. The population remained unchanged in 2000.