In 1974 it was added to the National Register of Historic Places - the only surviving building in Milwaukee with a cast iron skin - a common technique from 1850 to 1870.

[1][2] James Baynard Martin moved from Maryland to Milwaukee in 1845, where he dealt in grain and real estate, and served as an insurance executive and banker.

Martin chose that type of building, and engaged Daniel D. Badger's Architectural Iron Works of New York to design it.

[1][5] Martin's new building was four stories tall with the basement somewhat exposed at the northwest corner - an Italianate-styled design, with round arches above the windows resting on paired decorative columns and iron surfaces deliberately grooved to look like blocks joined with mortar.

[4] Over the years the street-level storefronts have been modified, but the upper stories are largely intact, except that the cornice was cut back and some iron removed.