Gordon A. Pfeiffer is a Delaware book, postcard, book art, and ephemera collector and an original founder of the Delaware Bibliophiles. The Gordon A. Pfeiffer Delaware postcard and ephemera collection comprises over 1500 postcards depicting Delaware cities and towns, landmarks and events, and advertisements of goods and services in the First State between 1860 and 2008. The collection also contains over 250 QSL broadcasting cards used for promotional purposes by state radio stations.

Gordon A. Pfeiffer is a Delaware book, postcard, book art, and ephemera collector and an original founder of the Delaware Bibliophiles. The Gordon Pfeiffer nineteenth-century Delaware trade card collection comprises over one thousand trade cards of Delaware suppliers and merchants.