A cousin of Civil War General William T. Sherman, William P. Sherman graduated from Tobyhanna, Pennsylvania, grade schools and high school. He attended Saint Bonaventure College and Christ the King Seminary. On September 23, 1909, he was ordained a Catholic priest, and then did a year of postgraduate work at Catholic University, in Washington, D.C., before being assigned as assistant pastor of Saint Luke’s Church in Jersey Shore. He later served as assistant pastor at Saint Joseph’s Church in St. Joseph, Pennsylvania; Saint Ann’s Church in Freeland; Saint Joseph’s Church in Athens; and then at St. Patrick’s Church in West Scranton, all in Pennsylvania. He was one of the first chaplains of his Diocese to volunteer for service during World War I, and was commissioned a U.S. Army chaplain on October 31, 1917, and left for France with the 6th Engineer Regiment less than two months later. He served from November 1917 until September 1922, when he returned to civilian pastorate at Holy Rosary Church in Scranton, Pennsylvania, and then at Saint Rose Church in Carbondale, Pennsylvania. He continued in ministry at other pastorates until his retirement from active ministry in 1931.