Natural history collections assembled before modern-day, anthropogenic declines in species occurrence and abundance can provide essential data for conservation and biogeographic research. Digitizing old, commonly 'orphaned' collections in small institutions without professional curators increases local community access to specimens, as well as global access to digitized data. We present a case study, documenting a 19th century freshwater mussel (Order: Unionoida) collection, which is part of the 'orphaned' natural history collections at Wesleyan University (Middletown, CT, USA). We curated this collection by identifying specimens according to present taxonomic practices, and using archival documents to recover metadata. Nearly 1900 specimens in 402 'lots', representing 155 species, were photographed and catalogued. Three primary type specimens were identified; 64 species are on the IUCN Red List, with 4 extinct, and 28 Critically-Endangered to Endangered. We created and publicly host online 3D models of imperiled species. These models enabled us to organize an exhibit of 3D prints of fragile specimens, and to study ecophenotypic variation of freshwater mussels along a river gradient. Our project documents the challenges and achievements of a case study illuminating the potential scientific value of, and revival strategies for, orphaned natural history collections.