Source:Irwin-estate-plan-1
From Pittsburgh Streets
"Plan of the subdivision of the Irwin estate: Situated between the A. V. Rail Road and Centre Street & 45th & 48th Streets City of Pittsburgh made at the request of G. S. Bates Esq." Laid out Dec. 12, 1870; recorded Jan. 17, 1871, Plan Book 4, pp. 70–71. Allegheny County Recorder of Deeds 3778844.
