Historic Fourth Street contains the many examples of commercial buildings in the 1880's in Sioux City. Names like the Bay State, Plymouth, and Major link these blocks to their Massachusetts investors. Most of the larger buildings in the district are notable for their distinctive Richardsonian Romanesque style, an architectural style popular in the late 1800s.

Two blocks long from Virginia to Iowa Streets, Historic Fourth contains 15 buildings dating from 1889 to 1915. Two of the buildings, the Evans' Block and the Boston Block are listed on the National Register of Historic Places.