Milwaukee, Milwaukee County WI – The Wisconsin Historical Society announces the listing of the A.O. Smith Corporation Headquarters in the National Register of Historic Places on October 11, 2022.

The A.O. Smith Corporation Headquarters Historic District is comprised of four remaining buildings of the original headquarters and factory complex from 1910 to 1997. It also includes portions of the surrounding landscape plan designed by the Olmstead Brothers, a noted landscape architecture firm founded by Frederick Law Olmstead.

The buildings housed A.O. Smith’s executive offices, global headquarters and their highly prized Research and Engineering Departments, as well as the world’s first automated assembly plant. Initially notable for its contributions to the automotive industry as a manufacturer of automobile frames, A.O. Smith went on to apply their innovative welding techniques and mastery of metal to other industries including brewing, agricultural storage, oil, natural gas and water heating, and played a significant part in both World Wars.

Several of the technologies A.O. Smith contributed to the World War II effort were also developed and tested in the Research and Engineering Building, including bomb casings for large capacity bombs, a new type of aircraft propeller and landing gear, torpedo air flasks, nose frames for the B-25 bomber and components for the atomic bomb project.

The Research and Engineering Building was designed in 1931 by master architects of national significance, Holabird and Root. It is one of the first, if not the first, buildings in the world with full-height curtainwalls of large plate glass in aluminum frames and the first to use extruded aluminum for this purpose.

The complex also includes the world’s first automated automotive assembly plant, dubbed the Mechanical Marvel. The plant increased productivity of the company’s automotive frame division by an astounding 3700%, dropping the price of frames and making A.O. Smith the primary manufacturer of automobile frames in the country.

The A.O. Smith Corporation and Headquarters Historic District holds a national level of significance due to the aforementioned architectural and industrial advancements that occurred on the property.

Additional information for the A.O. Smith Corporation Headquarters is available at:

To learn more about the State and National Register programs in Wisconsin, visit:

About the Wisconsin Historical Society

The Wisconsin Historical Society, founded in 1846, ranks as one of the largest, most active and most diversified state historical societies in the nation. As both a state agency and a private membership organization, its mission is to help people connect to the past by collecting, preserving and sharing stories. The Wisconsin Historical Society serves millions of people every year through a wide range of sites, programs and services. For more information, visit

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