The war years, 1941-1945, brought economic recovery to the nation. From all the parishes, so many men sacrificed their lives for our freedoms. Those who came home found a new acceptance for Catholics. Because these Catholic men had fought side by side with those of other faiths, opportunities began to open for Catholics that had previously been reserved for others. Some went to college with the G. I. Bill funds. Others began their families and moved out of the ethnic enclaves where they had grown up. The suburbs were calling, and the need for new parishes in those areas that were previously minimally populated by Catholics was evident.
Father Woshner died in 1943, and Father Paul Lunskis served Saint Vincent de Paul Parish as Administrator throughout the 1940’s and 50’s, with help from the Spiritan Fathers who were associated with Duquesne University.
One of those suburban areas was Moon Run, where a mission church under the patronage of the Holy Trinity had been formed as part of Saint Columbkille Parish, Imperial, back in 1908. Now, in 1944, Bishop Boyle erected Holy Trinity Parish from the former mission. The bishop appointed Father Giles Krysmalski as the first pastor. Fr. Kris, as he was affectionately known, possessed great organizational skills, and under his leadership the parish would grow in the coming decades.
The 164 families of the new parish worked together to provide a rectory for their pastor. It was realized in 1946, along with a social hall. The completion of the Parkway West and the presence of the Greater Pittsburgh Airport brought more people to the area, with the parish census reaching 198 families after just two years.
Father Poszukanis, pastor of Saints Cyril and Methodius, suffering from ill health, offered his resignation in 1945, after twenty years of service. His replacement was Father Francis Filip. Already the parish was beginning to show some shrinking, with only 84 students enrolled in the school, and 250 families registered in the parish, down from a decade before. As a result, in early 1946, Father Filip organized a census that included visits to former parishioners who had migrated to the suburbs. The parish increased their registration to 435 families. To meet the new growth in the parish, a Lyceum was organized so that young members of the parish would have a place for social activity, and an auditorium was dedicated.