[1] McGuinness was named assistant director of the local Society for the Propagation of the Faith, then as field secretary in 1919.
[1] McGuinness served as executive secretary of the American Board of Catholic Missions from 1923 to 1937, and was named a domestic prelate by the Vatican in 1929.
[2] He received his episcopal consecration on December 21, 1937, from Cardinal Dennis Dougherty, with bishops William O'Brien and Hugh L. Lamb serving as co-consecrators.
[2] During his nine-year administration, McGuinness saw the Catholic population in the state grow by almost 40 percent and received 1,242 adult converts in 1957 alone.
[3] Priestly and religious vocations flourished, and he made trips to Ireland and Poland to recruit clergy.