The 1893 Columbian Exposition in Chicago was sometimes called “The White City” and is said to have inspired the Emerald City of Oz in the 1899 collaboration between L Frank Baum and W W Denslow. Denslow left San Francisco to document the Chicago fair for local newspapers, and visited it frequently. Baum also moved to Chicago in anticipation of the Expo and certainly visited as well. Indeed, the domes of the White City, shown below, do bear a strong resemblance to components of Denslow’s Emerald City in The Wonderful Wizard of Oz.
The temporary buildings were mostly destroyed after the Expo, and Denslow had vanity photos taken of himself in the ruins. They were published in the Inland Printer in 1895. Thanks to Peter Hanff for the image below of a sporty Denslow lounging. 
This wasn’t the last connection between W W Denslow and the 1893 Expo. He revisited it almost 20 years later, in one of the scenes in Fairbank’s Juvenile History of the United States, a 1911 advertising booklet for Fairy soap!
