Diaz de la Peña, Narcisse Virgile. "A Lady with a Dog", 1913

This subseries is comprised of receipts, invoices, correspondence, loan forms, photographs, clippings, and other material documenting works of art owned, sold, or considered for purchase by Henry P. McIlhenny. Most of the files pertain to French paintings, as this was McIlhenny's particular area of collecting interest, although there are also files on the British painters whose works McIlhenny acquired to decorate his Irish castle, Glenveagh, most notably, Sir Edwin Landseer. Documentation regarding works owned by McIlhenny's father, mother, and sister is intermingled. Files related to the elder McIlhenny's collection are easily distinguished by their early date, and most commonly pertain to Old Master painters, including Sano di Pietro, Fra Mariano Angeli, and Domenico Campagnola. Such files commonly contain correspondence with W. R. Valentiner, John D. McIlhenny's personal consultant for art collection matters. A folder of additional letters from Valentiner is included in the "Dealers, museums and others" subseries. A few invoices from dealers to Valentiner as he purchased on behalf of McIlhenny are also included.

Material pertaining to McIlhenny's collection primarily dates from the late 1930s to the late 1970s, and provides a broad overview of how he built and administered his superb collection. There is significant documentation of McIlhenny's many negotiations with dealers for purchases, sometimes made in part by exchange of other works. A few files include documentation of the disposition of works through auction, including Paul Cézanne's "White Sugar Bowl," Pierre-Auguste Renoir's "Judgment of Paris" and Georges Seurat's "Le Poseuses." Numerous files include incoming loan requests from museums, many of which McIlhenny granted. During periods when McIlhenny was not easily reachable, specifically when he was actively serving in the military, his sister was responsible for overseeing these requests, as evidenced in the papers.

Of particular note are two original documents dating from 1817-1821 that seemingly relate to supplies and other expenses incurred by the artist Gericault.