The 955-unit, 40-story Outer Drive East was the firm’s largest commission to date, in 1961, and became the largest apartment building in the United States upon its completion in 1964. Built with air rights over the Illinois Central rail yard, Outer Drive East called on all the design and political skill that Chicago architecture could muster. It was a “machine for living,” to use Le Corbusier’s modern expression, with innovative radiant heating, central air conditioning, and even a newfangled telephone system.