Building Info

Construction workers putting finishing touches on the Iron Block Building.
  • Address:
    205 E. Wisconsin Ave.
  • Taxkey:
  • Architect:
    George H. Johnson, Architectural Iron Works
  • Architectural Style:
    Renaissance Revival
  • Status:
  • Assessment:
    $3,337,000 (2015)
  • Year Built:
  • Size:
    40,670 sq-ft

Recently restored office building located at the intersection of N. Water St. and E. Wisconsin Ave. The best example of cast-iron architecture in Milwaukee.

From the 1981 Landmarks Commission/Department of City Development report…

The Iron Block ranks among Milwaukee’s most important Civil War era buildings. It is the only remaining major example of cast-iron architecture in Milwaukee and is one of a few of its kind left in the Midwest. The Iron Block was built in 1860-61 for James B. Martin, a grain dealer, real estate agent, insurance executive and banker. Originally known as the Excelsior Block or Masonic Hall (the Excelsior Masonic Lodge had its meeting rooms on the top floor) and at times referred to as Martin’s Block, the building was not widely known as the Iron Block until after 1880.

The architect was George H. Johnson, manager of the architectural department of the Daniel Badger’s Architectural Iron Works in New York City. Badger and James Bogardus were pioneers in the prefabrication of cast-iron and its used in building technology. From Badger’s company one could order by catalog a variety of pilasters, columns, window fenestrations, cornices and entablatures which could be shipped to the site, bolted together and erected. The use of cast-iron facades was widely accepted for the materials’ fireproof qualifies and economical cost. Unusual to its design is a foundation of inverted semi-circular arches of brick between the courses of stone. It was believed that foundations of this type would reinforce the walls against inward collapse and distribute the vertical load over a greater wall area.

The design of the Iron Block was influenced by the North Italian Mode of the Renaissance Revival which first appeared in the United States around 1850. It was a style of sculptural ornament which created strong contrasts using light and shadow. The cheap cast-iron technology greatly popularized the style and was commonly used in commercial architecture over the next thirty years.

When it opened, Milwaukee’s Iron Block was prestigious business address. It initially housed a bank, four stores, numerous offices, and a law library. Painted white, the structure was a striking commercial block int he heart of downtown Milwaukee.

Through the years it has significantly altered. All of the original ground floor has been removed and the cornice has been severely cut back. The interiors have been substantially remodeled. However, an elevator installed in 1879 is still in use and is believed to be the oldest one still operating in the Midwest.

From Guides to Historic Milwaukee: Juneautown Walking Tour by Mary Ellen Pagel and Virginia Palmer (1965)…

J. B. Martin asked the designer of his office building to use a new form of construction which he had admired in New York City. Johnson complied, and cast-iron units for the street facades, planned to resemble those on fashionable eastern store fronts, were shipped to Milwaukee by schooner from the Rochester (New York) Iron Works. When the building was completed, several Masonic lodges rented quarters in the upper stories, and Martin named the block Excelsior in honor of the lodge to which he belonged. But the public, fascinated by the ususual cast-iron construction, refused to call the building anything but Martin’s Iron Block. Looking at the building’s North Water Street side, one detects the location of its entrance in the days when the heaviest traffic was along this street.


Show All


Low Voltage Permit.
ROW Occupancy Permit.
ROW Occupancy Permit.
ROW Occupancy Permit.
Electrical Permit.

Press Releases Referencing Iron Block Building