The Original Guaranty Building Elevators
Research by Craig Woodward and Harry Meyer

The Guaranty Building originally (1896) had elevators which were operated with SpragueElevators motors. 

Frank J. Sprague (1857-1934) was an electrical engineer andentrepreneur, an electrical pioneer. He initially worked for Thomas Edison but resigned and formed the Sprague Electric Railway and MotorCompany (1884-1890). He became a leading provider of electric motors and in 1888 installed the first major electric trolley car system inRichmond, Va.

In the late 1880's most elevators were steam or hydraulic driven; thedesign of the few electric motor-driven elevators in service was not suitable of passenger service in the high rise buildings then underconstruction in large cities.  Sprague combined his electric motor andcontrols with an apparatus developed by Charles Pratt and formed the Sprague Electric Elevator Company (1890-1932). The Guaranty Buildinghad one of the early Sprague elevator installations.

The Guaranty was owned from 1895 to 1900 by The Guaranty Building Company (“GBC”) controlled by the principals of The Guaranty Construction Company, but included as minority shareholders most of the major players who worked on the Building or supplied materials, including Louis Sullivan, Dankmar Adler, Northwestern Terra Cotta Co, East Tennessee Stone Marble , and several others. In 1898 the Building was refinanced at a lower interest rate by The Prudential Insurance Company  , which had also became a significant tenant, and the Building was renamed The Prudential Building.  In 1900 the title to the Building was quietly transferred to a new corporation  The Prudential Building Company  (“PBC”) and quite possibly those minority shareholders who worked on the Building or supplied  materials were “taken out” . However PBC apparently was still substantially controlled by the principals of The Guaranty Construction  Company  as that corporation’s President George Moulton , was also President of PBC and had been President of  GBC  [Moulton was a mover and shaker in Illinois Republican circles, went  to Cuba with Theodore Roosevelt, and was ultimately elevated to General and appointed the first Mayor and Police Chief of Havana after the Spanish American War] Mouton was still President of PBC in their 1901 Annual Report.  He did step down later  as President but remained a Director in 1903 when the Building was again refinanced, at an even lower rate, this time with Northwestern Mutual Insurance Company (then of Milwaukee)