 By 1900 , the burgeoning industrial town had 4 @,@ 600 residents and two years later Reverend Bonaventure Piscopo , a member of the Apostolic Band for the Roman Catholic Diocese of Pittsburgh , formed a new congregation in New Kensington to serve the immigrant work force , many of whom were Italian Catholics . The church was named after Saint Peter , the first pope . The parishioners of this new congregation were Italians living in and around New Kensington , Arnold , and Parnassus , which later became a part of the city of New Kensington . These immigrants needed a place to worship and in 1903 , the St. Peter congregation began holding Mass with a resident pastor , Reverend Vincenzo Maselli in a small building on the corner of Second Avenue and Tenth Street ( known as the downtown area ) in New Kensington . 
