Architecture of Chicago a new structural system of framed tubes in skyscraper design and construction. The first building to apply the tube-frame construction was the DeWitt-Chestnut Apartment Building which Khan designed and was completed in Chicago by 1966. This laid the foundations for the tube structures of many other later skyscrapers, including his own constructions of the John Hancock Center and Willis Tower (then named the Sears Tower) in Chicago and can be seen in the construction of the World Trade Center, Petronas Towers, Jin Mao Building, and most other supertall skyscrapers since the 1960s. Willis Tower would be the world's tallest building
The Gogo Building district along the Chicago River. There are two large red brick buildings along the Chicago River just south of where the river splits, formerly known as the Butler Brothers Warehouse buildings. They were both designed for the Butler Brothers Company, a mail order company, similar to Montgomery Ward's and Sears & Roebuck at the time. The northern structure was designed by Daniel Burnham, a famous Chicago architect, with its completion date being 1913, a year after Burnham’s death. This building only stood for 7 years before being completely demolished and rebuilt exactly as it stood before by the Chicago Union