Allegheny Square (Presently Campbell Square): Plan of Allegheny Square, 25th ward. Details of section of granolithic coping surrounding square and plan of opening in the pavement for tree planting. Department of Public Works, Bureau of Surveys. [ID: 12B-567; PWD ERV: 1075973; Drawing No.: 6953], 1896 May, Drawer: N1, Folder: 2.1. Philadelphia Water Department 12B - Drawings Donation, FP.2019.002. Fairmount Park Historic Resources Archive. https://pprarchives.libraryhost.com/repositories/2/archival_objects/4871 Accessed April 20, 2025.