In 1915, after just nine years in business, the bank was ready to expand and constructed its own new building just across the street on the northwest corner of Fifteenth and Cass. Cass purchased this prime location for $13,500. Later the Cass building would be leased to the Post Office when Cass expanded and moved yet again.
At the Stockholders Meeting in 1929, it was proposed to transform Cass Avenue Bank into a trust company, and thus the name was changed to Cass Bank & Trust Company.
Cass Avenue Bank moved into its newly constructed building at 13th and Cass Avenue in May, 1927, where it continued operations until 1974. In 1990 this building was donated to the City of St. Louis and is now the Bus Terminal.
In 1941, Cass Bank advertising included the promise: “Park Free While You Bank”…one of the first St. Louis area banks to offer this modern amenity. By 1957, Cass also offered walk-up and drive-up windows for its customers’ convenience.