<P> The Congress Plaza Hotel is located on South Michigan Avenue across from Grant Park in Chicago at 520 South Michigan Avenue . After opening for business in 1893, for the World's Columbian Exposition, the hotel underwent two major expansions and renovations; it now features 871 guest rooms and suites . Its 11 story edifice was originally designed by architect Clinton J. Warren as an annex to the Auditorium Theater across the street . The two buildings were linked by a marble - lined underground passage called Peacock Alley . In 1902 and then in 1907, the firm of Holabird & Roche oversaw the design and construction of two additions, bringing the total complex up to 1 million square feet . </P> <P> In June, 1912, Theodore Roosevelt stayed at the Congress Plaza when the 1912 Republican National Convention was held in Chicago . Roosevelt, who at that time was seeking the Republican nomination for President, spoke from the balcony of his room at the hotel to a crowd assembled across the street in Grant Park . </P>

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