Peck persuaded many Chicago business tycoons to go on board with him, including Marshall Field, Edson Keith, Martin A. Ryerson, Charles L. Hutchinson and George Pullman.

The association hired the renowned architectural firm of Dankmar Adler and Louis Sullivan to design the building.

The rest of the building is a uniform ten stories, organized in the same way as Richardson's Marshall Field Wholesale Store.

The interior embellishment, however, is wholly Sullivan's, and some of the details, because of their continuous curvilinear foliate motifs, are among the nearest equivalents to European Art Nouveau architecture.

[8] One of the most innovative features of the building was its massive raft foundation, designed by Adler in conjunction with engineer Paul Mueller.

The soil beneath the Auditorium consists of soft blue clay to a depth of over 100 feet, which made conventional foundations impossible.

Adler and Mueller designed a floating mat of crisscrossed railroad ties, topped with a double layer of steel rails embedded in concrete, the whole assemblage coated with pitch.

This deflection is clearly visible in the theater lobby, where the mosaic floor takes on a distinct slope as it nears the outer walls.

Most of the settlement occurred within a decade after construction, and at one time a plan existed to shorten the interior supports to level the floors but this was never carried out.

Housed in the building around the central space were an 1890 addition of 136 offices and a 400-room hotel,[8][9] whose purpose was to generate much of the revenue to support the opera.

The 1888 Republican National Convention was held in a partially finished building where Benjamin Harrison was nominated as a presidential candidate.

[8] In 2001, a major restoration of the Auditorium Theatre was begun by Daniel P. Coffey and Associates in conjunction with EverGreene Architectural Arts to return the theater to its original colors and finishes.