Hancock County Bank opened on October 9, 1899. Weeks later, the bank's board of directors purchased property at the corner of Main Street and South Beach as the site of a new headquarters. Bay St. Louis's first two-story brick building, the bank was constructed by John T. McDonald and completed in September 1900. The building later housed a post office and a United States customs office. It was renovated after suffering extensive damage from Hurricane Camille in 1969 and Hurricane Katrina in 2005.