The Mackie Building is a grand commercial building designed by E. Townsend Mix and built in 1879 in Milwaukee, Wisconsin, which housed Milwaukee's Grain Exchange Room, and the original trading pit.

The exterior remains much as Mix designed it: five and a half stories, plus a tower centered above the main entrance, reaching 160 feet above the street.

The north entrance is framed by granite columns and images of the Great Seal of Wisconsin and the bull and bear.

The room was designed in a Simple Italian architectural style, with soaring ceilings, hand painted frescoes, gold leaf and over 10,000 sq.

The grain exchange is closely linked with the early commercial history of Milwaukee, when for a brief time, the city was the world's largest primary wheat market for trading, exporting and inspecting grain.