Ad Hall is located just off U.S. Highway 190 on Farm Road 486 six miles west of Cameron in western Milam County. The post office, named for early settler Adam J. Hall, was opened in 1874, and the community became a voting precinct in 1880. The Gulf, Colorado and Santa Fe Railway passed within a half mile of Ad Hall when its track was built through the area in 1881. The community enjoyed a brief period of prosperity in the 1880s, when it had a cotton gin, a gristmill, three churches, a district school, and 200 residents. In the 1890s, however, the population fell to thirty-five. The post office was discontinued in 1912, and by the 1930s only fifteen residents were reported. A school, a business, and several scattered houses marked the community on county highway maps in 1948. The school closed in 1958, and the students were sent to Cameron. A church and two cemeteries were all that appeared on county maps in 1988. No population estimates were available in 2000.