OPLIN, TEXAS. Oplin, on State Highway 604 and Farm Road 2926, south of the Middle Fork of Pecan Bayou in southwestern Callahan County, dates from the 1890s. A post office was established in 1903 with William A. Smith as postmaster. The name Oplin was suggested by local merchant Steve Jones and supposedly came from that of a South American town. The population peaked at 300 in 1915 and fell off to 100 in 1925. In 1940 the community had 200 residents, five businesses, a school, and a cemetery, but it suffered a decline during and after World War II,^qv paralleling the decline in Callahan County and possibly reflecting the increasing attraction of cities like Abilene as transportation and communications improved. The post office in Oplin closed around 1961. In 1990 the population was reported as seventy-five. The population remained the same in 2000.