Gulfport was incorporated on July 28, 1898. Gulfport was founded by two men: William H. Hardy who was president of the Gulf and Ship Island Railroad (G&SIRR) that connected inland lumber mills to the coast, and Joseph T. Jones who later took over the G&SIRR, dredged the harbor in Gulfport, and opened the shipping channel to the sea. In 1902, the harbor was completed and the Port of Gulfport became a working seaport that now accounts for millions of dollars in annual sales and tax revenue for the state of Mississippi.
In 1910, the U.S. Post Office and Customhouse was built. The Gulfport Post office was listed on the National Register of Historic Places in 1984.