This is the Willis Tower located in 233 South Wacker Drive, Chicago. It was formerly called Sears Tower. It is 422 meters or 1,451 feet high and is a 108-story skycraper. It was the tallest building in the world at the time of its completion in 1974.
The Willis Tower is the tallest building in the United States and the fifth-tallest freestanding structure in the world, as well as the fifth tallest building in the world to the roof.
Willis Tower remains the tallest building in the Americas. With a pinnacle height of 1730 feet (527 m), it is the second tallest freestanding structure in the Americas, as it is 86 feet (26 m) shorter than Toronto’s CN Tower, and is the only other freestanding structure in the Americas to exceed 1500 feet (457.2 m) in height. As of August 2009, Willis Tower is the fifth tallest freestanding structure in the world (by pinnacle height), after the Burj Khalifa, the Canton Tower, the CN Tower and the Ostankino Tower.
At 1,482.6 feet (451.9 m) tall, including decorative spires, the Petronas Twin Towers in Kuala Lumpur, Malaysia, laid claim to replacing the Sears Tower as the tallest building in the world in 1998. Not everyone agreed, and in the ensuing controversy four different categories of “tallest building” were created. Of these, Petronas was the tallest in one category (height to top of architectural elements, meaning spires but not antennas). more about Willis Tower here