THE ‘L’ CHICAGO The Willis Tower, mostly remembered by its original name, the Sears Tower, is an iconic symbol of Chicago like the Chicago Transit Authority’s elevated train public transportation system. Once a hodgepodge of competing rail lines consolidated in the 1940s when it went public and commonly referred and known as the “L”. It is the fourth largest rapid transit system in the United States, third by volume, serving Chicago proper and the surrounding suburbs.