The U.S. Post Office was designed in the office of the Supervising Architect of the Treasury Department by James Knox Taylor in 1906-07, and reflects the prevailing design ideals of that era with its Beaux Arts Classicism and Second Renaissance Revival influences. An addition to the north end of the building, completed in 1941 by the James Leck Co. of Minneapolis, blends seamlessly with the original structure. Plans for the addition were drawn in the office of Louis A. Simon, Supervising Architect for the Federal Works Administration under the direction of W. G. Noll, Chief of Architecture. A two-year $7.7 million renovation of the building was completed in 1993.