PITTSBURGH, DIOCESE OF. - City and diocese in the State of Pennsylvania, U.S.A. The diocese of Pittsburgh, suffragan of Philadelphia, today covers a territory of 7,238 square miles, has a total population (1950 census) of 2,799,675 inhabitants, of whom 832,745 are Catholics (1951). There are 1,020 priests, of whom 262 are religious from 9 different congregations; 416 parishes, 267 chapels, 65 missions, 44 female congregations with 4,612 religious; 4 colleges and universities (Duquesne University, run by the Fathers of the Holy Spirit); 4 orphanages, 10 hospitals, and 5 homes for the elderly.
PITTSBURG, DIOCESE OF - View of the city and, in the foreground, the institute for industrial research.
It is highly probable that the Jesuit Bonnecamp held the first religious service for whites in the diocese in 1749. The city of Pittsburgh was so named to honor William Pitt, Prime Minister of England, when the British army took possession of Fort Duquesne in 1758, later called Fort Pitt or Pittsburgh. With the French having left the territory, the Catholic religion had almost no presence in western Pennsylvania for about 30 years, and the Catholics who settled there were opposed by the Calvinists.
The first church in Pittsburgh, still known today as "Old St. Patrick's," was opened in August 1811. As early as 1825, Bishop Benedict Joseph Flaget considered Pittsburgh as the seat of a future diocese; only in 1836 did Bishop Francis P. Kenrick propose the division of the Diocese of Philadelphia. In January 1836, the Rev. John Hughes was appointed bishop of the new see of Pittsburgh, but shortly afterward Rome annulled the appointment. On May 14, 1843, with the division of Philadelphia, the Fifth Provincial Council of Baltimore again proposed to the Holy See the erection of the Diocese of Pittsburgh. With the brief *Universi Domini gregis* of Gregory XVI, Pittsburgh was erected on August 8, 1843, for the western part of Pennsylvania; Bishop Michael O'Connor was the first bishop, consecrated in Rome on August 15 and took possession on December 3 of the same year. After great activity in the diocese, he entered the Society of Jesus; he founded a diocesan seminary and called the Oblates of Mary Immaculate from Canada to run it, but only for a short time. In 1852, the diocese was so prosperous that its division was considered. The First Plenary Council of Baltimore, held on May 10, 1852, made the proposal to Rome. Indeed, on July 29, 1852, the Diocese of Erie was erected. Pittsburgh was then reduced to 11,314 square miles. Under Bishop M. Domenec, successor of Bishop O'Connor, the diocese was again divided to form the Diocese of Allegheny City, but only for a short time because that see was suppressed. In 1901, the Holy See erected the Diocese of Altoona by dividing Pittsburgh and Harrisburg.