Construction of the Catholic Cathedral Basilica of Saints Peter and Paul had begun in 1846, following the design of native Philadelphian, Napoleon Le Brun. Though itt was not completed until the following year, the structure was far enough along for the Catholic Diocese of Philadelphia to host an open day. More than two thousand people attended and Bishop James Frederick Wood, later the first Catholic Archbishop of Philadelphia, spoke. The Basilica remains the largest Catholic church in Pennsylvania; Pope John Paul III held mass there in 1979. (By John Osborne)