Chicago Board of Trade Building

"In 1925, the Chicago Board of Trade commissioned Holabird & Root to design the current building. Clad in gray Indiana limestone, and topped with a copper pyramid roof, the art deco-styled building opened on June 9, 1930. The Chicago Board of Trade has operated on its fourth floor since the 1930 opening, dedicating 19,000 square feet to what was then the world's largest trading floor. - Took advantage of 1923 Zoning Ordinance - Art Deco style - Ornamentation reflects what is occurring in the building The advent of steel frame structural systems allowed completely vertical construction; but as with many skyscrapers of the era, the exterior was designed with multiple setbacks at increasing heights, which served to allow additional light into the ever-deepening concrete valleys in urban cores. At night, the setbacks are upwardly lit by floodlights, further emphasizing the structure's vertical elements. The night illumination design was a common contemporary Chicago architectural theme, seen also in the Wrigley Building, the Jewelers Building, the Palmolive Building, the LaSalle-Wacker Building, and the Tribune Tower. (view from outside the Rookery building)"