End of the informal height limit - One Liberty Place

For roughly eight decades an informal 'gentlemen's agreement' in Philadelphia kept new downtown buildings lower than the brim of the William Penn statue atop City Hall. Completion of One Liberty Place in 1987 at 1650 Market Street exceeded that height and effectively ended the unwritten limit, triggering a subsequent wave of taller skyscraper construction in Center City. The tower was designed by architect Helmut Jahn and marked a clear change in the city's skyline policies.