For four decades, Chicagoans have been able to one-up New Yorkers on at least one measure: The City of the Big Shoulders had the tallest building in the United States.

But as of Tuesday, that crown is moving east. One World Trade Center in Lower Manhattan has officially been ruled to be taller than the Willis Tower, in Chicago. That judgment came from the primary arbiter of structural stature, the Council on Tall Buildings and Urban Habitat.