Roman Catholic Diocese of Allegheny

[4] Bishop Domenec resigned the See of Allegheny 27 July, 1877, and retired to his native land, where he died at Tarragona, 7 January, 1878.

[5] At its creation, the Diocese of Allegheny covered eight counties and an area of 6,530 square miles (16,900 km2), leaving the Diocese of Pittsburgh with six counties and an area of 4,784 square miles (12,390 km2).

Andrew Lambing, an early historian of the Catholic Diocese of Pittsburgh, described the boundary lines as follows: The dividing line between the sees of Pittsburgh and Allegheny started at the southern boundary of the State between Bedford and Somerset counties, and passed north till it reached Cambria, and thence west to Westmoreland.

Passing along the eastern, southern, and western boundary of this county, it struck the Allegheny River, and passed down that stream and the Ohio to the western limits of Allegheny City.

From that point it struck due north through Allegheny County to the southern boundary of Butler, and continued west and north to the line dividing Lawrence and Mercer counties.