The Mackie Building and the world's first octagonal trading pit

The Mackie Building, a historic commercial and residential structure, proudly stands on East Michigan Street 225, in the city of Milwaukee. A dream of Scottish immigrant and U.S. Representative Alexander Mitchell, the Mackie Building was designed by E. Townsend Mix in 1879, in the style of Victorian architecture. Initially known as the Chamber of Commerce, it welcomed the Milwaukee Grain Exchange, a commercial hub for trading agricultural products.

This three-story tall trading floor played a significant role in Milwaukee's wheat market, briefly earning the city the title of world's largest primary wheat market. The Milwaukee Grain Exchange was a pioneer, utilizing the world's first octagonal trading pit, a concept that was later replicated in many other trade exchanges throughout the country. The grain exchange operated from 1880 to 1935 before the building was added to the National Register of Historic Places in 1973.

The building was renovated in 2016 by developer Joshua Jeffers, renovating the former office space in the upper floors into apartments, and converting the Grand Exchange Room into a private venue space. The exterior, clad in gray Minnesota granite and sandstone, retains much of its original design. Its windows, different at each story, are unified by alternating bands of color and texture. The roof is a complex of mansards, with the north entrance framed by granite columns and images of the Great Seal of Wisconsin, including the bull and bear.

The interior mirrors much of the exterior's design, with large, gray-granite and sandstone pillars and walls, stained glass, and frescoes and other detailing on the ceiling, as well as significant gold leaf adornments, metalwork, and large paintings and murals lining many of the walls.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons