While compiling catalogs, our first Big Three retailer was also adding real estate to the Windy City skyline. The Tower Building seen here, completed in 1906, housed the corporate offices of Montgomery Ward & Company. At the time, the 25-story structure was the tallest building in Chicago.
Photo from University Library / University of Illinois Champaign & Urbana

In 1926, J.C. Penney moved into this 18-story structure in Manhattan. A new International-style corporate headquarters was completed in 1964.
Photo from Wikimapia / "John832" 

Back in the Windy City, Sears' new corporate headquarters was completed in 1973. Extending upward for 108 floors, the Sears Tower was the world's tallest building for 25 years. As a footnote: to us at the Mall Hall of Fame, this building will ALWAYS be referred to as the (quote-unquote) "Sears Tower," no matter what company has bought and renamed the structure.
Photo from Wikipedia / Kelly Martin