Trivia: What is this building, originally named the Sears Tower?
John Hancock Center
Willis Tower
World Trade Center
Blackstone Tower
Correct Answer: Willis Tower
So why is this answer correct? : In 1969, Sears Roebuck and Company decided it needed a central office space for its 350,000 employees, so they commissioned a 1,730-foot tower in the heart of Chicago. After it was completed in 1973, Sears Tower was the tallest building in the world for 25 years. In 2009, the building was renamed Willis Tower after Willis Group Holdings, an insurance brokerage.