Willis Tower
That was in turn surpassed by the twin towers of New York’s original World Trade Center in 1972, which were in turn surpassed by the Sears Tower in Chicago in 1974. Now called the Willis Tower (since 2009) it was to its flat rooftop, or including its original antennas. But in 1978 One World Trade Center (commonly known as the north tower) attained a taller absolute height when it added its new broadcasting antenna, for a total height of . The WTC north tower maintained this height record (including its antenna) from 1978 until 2000, when the owners of the Willis Tower extended its broadcasting antennae for a total height of . Thus the status of the Willis Tower as the “totally” tallest was restored in the face of a new threat looming in the Far East—the “Siamese Twins.”