"Plan of the subdivision of the Irwin estate: Situated between the A. V. R. R. Centre St. 45th & 47th St's. Pittsburgh Pa. made at the request of G. S. Bates, Esq." Laid out Dec. 1870; recorded July 27, 1880, Plan Book 6, p. 222. Allegheny County Recorder of Deeds 3779443.
