Beginning operations in 1909, the San Antonio and Rio Grande Railway Company became a branch of the St. Louis, Brownsville and Mexico Railway in 1912. Nicknamed "Old Flossie," it provided freight and passenger transportation to the new towns of Chapin (Edinburg) and San Juan during a crucial time in the area's development. Passenger service decreased after World War II, and the line was limited to freight service. It was absorbed by the Missouri Pacific system in 1956. By the late 1960s all service to San Juan and Edinburg ceased, the rails were removed, and the depots were razed.