Philadelphia views--Street scenes--20th century Architecture--20th Century 1 Built environment--Pennsylvania--Philadelphia--20th century 1 Delaware River Bridge 1 Labor--20th Century 1 Philadelphia Views--Street Scenes--19th century 1 Poverty--20th century 1 more ... Recreation--Bicycling 1 River engineering--Pennsylvania--Philadelphia 1 Sewerage--Pennsylvania--Philadelphia 1 Subways--Philadelphia 1 Taverns (Inns)--Philadelphia--History 1 less ...