WILLISA TOWER (Formerly SEARS TOWER)
Standing tall above every other skyscraper in Chicago, Willis Tower (formerly known as the Sears Tower) is a 110-story building in the heart of downtown. One of the tallest buildings in the world and the tallest building in America, it is impossible to miss when appreciating the skyline. In 1969, Sears Roebuck and Company was the largest retailer in the world, with about 350,000 employees. Deciding it needed a central office space for its many employees, the company hired architects Skidmore, Owings and Merrill to design what would become one of the largest office buildings in the world. After breaking ground in 1970, it took three years to complete and used enough concrete to make an eight-lane, five-mile-long highway. The last beam put in place was commemorated by the signatures of 12,000 construction workers, Sears employees, and Chicagoans.