These 7 Skyscrapers are the Only Ones to be Called The World’s Tallest - Page 4 of 9

The Willis Tower, Chicago, IL, 1974 (1,451 feet)

Formerly known as the Sears Tower, the Willis Tower is the tallest building in Chicago. The building was constructed in 1970 because Sears Roebuck and Company, the largest retailer in 1969, needed more office space for its employees.

Fun fact: the final beam of the structure is adorned by 12,000 signatures of construction workers, Sears employees, and Chicagoans.