This is the fifteenth in a series of entries celebrating infrastructure achievements in the United States.
What: The Willis (Sears) Tower is the tallest building in America.
Where: The Willis (Sears) Tower is located on Wacker Drive in the heart of the West Loop in Chicago, IL.
When: Construction began on the tower in 1970 and was completed in May of 1973.
Height: Willis Tower is 1,450 feet (443 meters) high – 1,730 feet (520 meters) including twin antenna towers.
Interesting facts: The combined weight of the building is 222,500 tons – that’s 445,000,000 lbs., 201,849,000 kg, or almost 20,000 city buses!
Over a million people visit its observation deck every year.
On a clear day, you can see four states – Illinois, Indiana, Wisconsin and Michigan. Visibility from the Skydeck is approximately 40-50 miles (65 – 80 kilometers).
The average sway of the building is approximately 6 inches (152 millimeters) from true center, but the building is designed to sway up to 3 feet.
Sears’s naming rights expired in 2003, but the building’s name was not officially changed until March 2009, when a London-based company obtained the naming rights. On July 16, 2009, the building was officially renamed the Willis Tower.