Completed in 1986, this significant expansion made McCormick Place the largest convention center in the United States, a record it still holds. The project combined advanced engineering and the utilization of air rights to enable development on land once thought unbuildable. It also served as a successful model for subsequent expansions, as well as other pioneering air rights projects.

Constructed over active railroad tracks, the addition is divided into two distinct zones: a two-level exhibition hall and a storage area with loading docks. Enclosed pedestrian bridges connect the original building to the newer exhibition halls, meeting rooms, and administrative offices. SOM designed a suspended roof for the new building, creating the clear spans now common in world-class convention centers. The roof is supported by steel cables hung from 12 distinctive pylons that rise up through the building.