Willis Tower, The Year Chicago Was the Tallest City on Earth

When the Sears Tower was completed in nineteen seventy-three, it was the tallest building in the world, surpassing the World Trade Center in New York, which had held the record for only a couple of years. Chicago had been building tall since Louis Sullivan's day, since the steel skeleton made it structurally possible to stop worrying about how much a building's walls could hold and start thinking instead about how far up you could go. But nineteen seventy-three was different. This was not an architectural argument. It was an economic bet.

Downtown Chicago in nineteen seventy-three was in trouble. White flight to the suburbs had been accelerating for two decades. The department stores that had anchored State Street and the Loop were following their customers north and west to suburban shopping centers. The conventional wisdom among urban planners at the time was that American downtowns were finished, that the car had made density optional, that the city center would hollow out like the centers of Detroit and Cleveland were hollowing out.

Sears, Roebuck and Company decided to build the tallest structure in human history on Wacker Drive in the Loop. The reasoning was partly practical, consolidating their corporate operations from scattered suburban offices, and partly a statement: that Chicago's downtown was not finished, that someone was still willing to make a thirty-year bet on it.

The Sears Tower held the world's tallest title until nineteen ninety-eight, when the Petronas Towers in Kuala Lumpur surpassed it, twenty-five years at the top. The building is the Willis Tower now, renamed in two thousand nine when a British insurance broker took the naming rights. The bet Chicago made in nineteen seventy-three paid off, by most measures, though the downtown it was betting on has changed in ways that Sears could not have anticipated.