In 1987, construction was finished at One Commerce Square in Center City, with the building opening in October, but the complex was still unfinished as a second tower was planned. Two Commerce Square would rise at 2001 Market Street to the west of the first building, filling in a gap between the finished structure and the Independence Blue Cross Tower. The second tower rises 565 feet and 41 stories tall. Designed by I. M. Pei and Partners and developed by Maguire Thomas Partners of Los Angeles, the Commerce Square complex was completed in 1992 and this became last structure built in the 1980s boom after the unofficial Gentleman’s Agreement height limit was eliminated.
2001 Market Street
In 1984, the unwritten Gentleman’s Agreement that forbade building above the 548-foot-high statue of William Penn atop City Hall was about to be eliminated when, in April, developer Willard Rouse proposed a skyscraper development that eventually became Liberty Place. The proposal apparently influenced more developers and architects to build towers above the former height limit. The Commerce Square twin towers were revealed at 2005 Market Street in Center City at the end of the year. Designed by I.M. Pei and Partners and developed by IBM and Maguire/Thomas Partners, the 41-story towers were not built simultaneously, as One Commerce Square was the first building finished in the complex.
Philadelphia is home to many skyscrapers designed by well-known architects from around the world. Among these are the twin towers of Commerce Square, which were designed by the renowned firm of I.M. Pei & Partners. The 565-foot-tall One Commerce Square and Two Commerce Square towers are still prominent on the Philadelphia skyline to this day, and they take up an entire city block at 2001 Market Street and 2005 Market Street in Center City. Both of the 41-story structures are framed in steel, and each is topped with a decorative diamond on the east and west faces. Maguire Thomas Partners was the developer of the towers at the time of the completion of One Commerce Square in 1987 and five years when Two Commerce Square was completed, which was also the time when the developers decided to split their partnership.