Union Valley grew around a log schoolhouse on a site given by Harriet Smith Beaty in 1872 to trustees John Coleman, King Holstein, and Samuel McCracken. In 1877, that schoolhouse was replaced by a frame building on William Cone land that also served as a Masonic Hall, church, and courtroom. A post office opened in 1883, and the town included stores, gins, saloons, blacksmith shops, and butcher shops owned by Burnside, Cone, Creech, Dunn, Hightower, Hoy, Hudson, Irvin, Johnson, Murray, Magee, Patterson, Spear, Treadwell, Watkins, Wiley, and Wright. The town dwindled after the Galveston, Harrisburg and San Antonio Railroad bypassed it in 1906.