 He was then sent to continue his studies at the Catholic University of America in Washington, D.C., where he earned a doctorate in canon law in 1949.During his summers at the Catholic University, he served as a curate at St. Paul Church in Philadelphia, Maternity of the Blessed Virgin Mary Church in Philadelphia, and Our Lady of Mount Carmel Church in Doylestown.In 1949, Welsh became a professor at Southeast Catholic High School (now St. John Neumann High School) in Philadelphia.