1. Maps C.21.f.12(42) Reference (shelfmark): Maps C.21.f.12(42) Title: Centennial Opening, the Choristers [opening of the Philadelphia Centennial Exposition]. Photographer: Unknown Scope & Content: Genre: Historical Events View of crowds gathered in front of the buildings at the opening ceremony. Stereo half. Collection Area: Map Collections Languages: Not applicable Date Range: 1876 Extent: 1 item