Robstown began in 1903 at the merger point of the Texas-Mexican and the St. Louis, Brownsville and Mexico Railroads. The town grew rapidly after the arrival of land developer George H. Paul. He organized the George H. Paul Land Co., acquired about 300,000 acres of land from nearby ranches, and subdivided the property into cotton farms. Special trains transported Paul's land agents to the East and Midwest to interest prospective buyers in the area.
The hub of activities in the new community was the Paul Building, a two story red brick structure erected at this location in 1908. Its first floor was occupied by the Howard and Jacoby General Store. The multi-purpose building also housed Robstown's first school and a community room where church services were held. A windmill and well behind the structure provided the town's water supply.
The Guaranty State Bank, organized in 1913 by William H. ("Bill") Daimwood, occupied the Paul Building in 1924. Renamed the State National Bank of Robstown in 1925, it was noted for its stability in the Great Depression of the 1930s. The Paul Building was demolished in 1972, after the structure became unsafe, and a new bank facility was erected at the site.