Black text with blue background and white curl. Sears Tower is in the center surrounded by other buildings. The words "Sears" and "Tower" are placed vertically on each side of the Sears Tower image. Text arched over top of button reads "World's Tallest Building Chicago, Illinois."
The Sears Tower was the world's tallest building at the time of its completion in 1973. It supassed the World Trade Center towers in New York and held the title for nearly 25 years. It is now the tallest buiding in the US and the 5th tallest freestanding structure in the world. On July 16, 2009, it was officially named the Willis Tower after London-based insurance broker Willis Group Holdings.