Willis Tower
The tallest buildings in Chicago are Willis Tower, Trump Tower, the St. Regis Chicago, the Aon Center, and the John Hancock Center. Willis Tower was originally named Sears Tower, and was the tallest building in the world from 1973 to 1998. It is now the third-tallest building in the United States, after One World Trade Center and Central Park Tower, though the height to the roof of Willis Tower is greater than that of One World Trade Center.