Carl Otto Kretzschmar von Kienbusch (1884-1976) was a New York businessman who collected arms and armor from 1914 until his death. In 1963, Princeton University Library published a catalogue of the art collection. Following a decades-long relationship with the Philadelphia Museum of Art, he bequeathed, in 1977, his entire collection (along with its important library and archive) to the Museum where it was installed in a series of specially built galleries. The Kienbusch papers provide documentation of the Collection and biographical information. Correspondence and materials document his interactions with dealers, collectors, museums, and distinguished scholars. It includes an estate appraisal, copies of his will, inventories, receipts and invoices, drafts of articles, articles by others on the Collection, annotated auction catalogues, and genealogical files on the Kienbusch family. There is a large quantity of photographic material (over 40% of the collection): prints of objects in the collection and objects in other collections; glass and film negatives and photographs from Kienbusch's European travels; and lantern slides to accompany lectures. Personal papers include appointment books, travel diaries, autobiographies, a family history, photographs, tickets, receipts, and ephemera. The travel diaries and scrapbooks with photographs document collecting and study trips to Europe. Finally, the collection includes loose photographs of Kienbusch and his family members.