During sectarian riots, two Catholic churches were burned to the ground, another was saved only by military intervention. Virtually every Catholic church in Philadelphia County was threatened. Scores of houses were destroyed and dozens of people were killed. It happened in Philadelphia 169 years ago, but it still has lessons for today. The violence began in May and ended in August of 1844. It started in Kensington, where St. Michael’s Church was ultimately destroyed, spread to the older part of the city where St. Augustine’s was destroyed and flared up again in August when St. Philip Neri in the Southwark...