Willis Tower - Reaching for the Sky

Stop on Historic Chicago Loop Walking Tour, a free self-guided tour.

Conclude your tour at Willis Tower, 233 South Wacker Drive, formerly known as Sears Tower. When completed in 1973, this 110-story, 1,450-foot skyscraper was the world's tallest building for 25 years. Architect Bruce Graham and structural engineer Fazlur Rahman Khan of Skidmore, Owings & Merrill created the innovative bundled tube design. Nine square tubes rise together, with tubes dropping off at different heights creating the building's distinctive stepped silhouette. This revolutionary structure influenced skyscraper design worldwide. The black aluminum and bronze-tinted glass exterior gives the building a powerful presence on Chicago's skyline. The Skydeck on the 103rd floor attracts over a million visitors annually, offering views up to 50 miles on clear days. The Ledge, glass boxes extending four feet from the building, provides a thrilling experience suspended 1,353 feet above the street. Sears Roebuck built the tower as their headquarters when they were America's largest retailer. The building represents Chicago's continued dominance in skyscraper construction a century after inventing the form. Though no longer the world's tallest, Willis Tower remains an engineering marvel and powerful symbol of Chicago's architectural legacy, bringing your historic tour full circle from 19th-century innovations to modern engineering triumphs.