He was appointed Prefect Apostolic of Northern Nigeria (now the Roman Catholic Archdiocese of Kaduna) in 1930, serving until, he was appointed vicar apostolic (as well as titular bishop of Urusi) on 25 April 1933 and archbishop on 18 Apr 1950. He retired as archbishop on 15 May 1959.[3]
Schools
In 1936, Porter established a Roman Catholic secondary school, St. Augustine's College in Cape Coast.[4]
He also established several Roman Catholic youth groups.