Built in 1929, the building is a bold example of Art Deco architecture, including art moderne designs. At the top of the Guardian Building’s spire, is a large American flag, complementing the four smaller flags atop nearby 150 West Jefferson. The Guardian Building’s interior is lavishly decorated with mosaic and Pewabic and Rookwood tile. The semi-circular exterior domes are filled with Pewabic Pottery. The building was designated a National Historic Landmark in 1989. It was used as headquarters for production during World War II.