Loughlin was
ordained to the priesthood for the
Diocese of New York by Bishop
John Hughes on October 18, 1840 at
Old St. Patrick's Cathedral in Manhattan. After his ordination, the then served as a
curate at St. John's Parish in
Utica, New York, then part of the diocese. In 1841, the diocese transferred him to the Old St. Patrick's Cathedral Parish. In 1850,
Pope Pius IX raised the Diocese of New York to the Archdiocese of New York. That same year, Archbishop Hughes named Loughlin as his
vicar general. ==Bishop of Brooklyn==