History of the world's tallest buildings
The tallest building in the world, as of 2022, is Burj Khalifa. The title of "world's tallest building" has been borne by various buildings, such as the Rouen Cathedral and the Empire State Building.
CN Tower
The CN Tower is the tallest freestanding structure in the Western Hemisphere. As of 2013, there are only two other freestanding structures in the Western Hemisphere which exceed in height; the Willis Tower in Chicago, which stands at when measured to its pinnacle; and the topped-out One World Trade Center in New York City, which has a pinnacle height of , or approximately shorter than the CN Tower. Due to the symbolism of the number 1776 (the year of the signing of the United States Declaration of Independence), the height of One World Trade Center is unlikely to be increased. The proposed Chicago Spire was expected to exceed the height of the CN Tower, but its construction was halted early due to financial difficulties amid the Great Recession, and was eventually cancelled in 2010.