The papers of art historian and museum director Wilhelm Reinhold Valentiner measure 6.9 linear feet and date from 1853 to 1977. Found within the collection are biographical materials, including information on the Lepsius and Valentiner families; correspondence with family, friends, art collectors, and art historians; seven diaries; additional writings and notes; printed materials; three clippings scrapbooks; artwork in the form of prints and woodcuts; and photographs of Valentiner and his family and friends, including two photograph albums.

The papers of museum director Perry Townsend Rathbone measure 4.3 linear feet and date from 1929 to 1985. The papers document Rathbone's career as museum director of the City Art Museum of St. Louis and the Boston Museum of Fine Arts, and his later work with Christie's New York office. Found within the papers are biographical materials, correspondence with friends and colleagues, writings, professional and project files, printed materials, and photographs, mostly of exhibitions.

The papers of art historian E. P. Richardson measure 28.7 linear feet and date from 1814-1996, with the bulk of the materials dating from 1921-1996. Within the papers are scattered biographical materials; acquisition files for Richardson's personal art collection; professional and personal correspondence with colleagues, art historians and critics, artists, museums, galleries, and dealers; numerous writings, including manuscripts and research files for his published books, articles, and lectures; general research notebooks and files compiled by Richardson on a wide variety of art-related topics and artists; professional and committee files; as well as a smaller amount of Constance C. Richardson's papers.

The records of the Perls Galleries measure 79.6 linear feet and date from 1937 to 1997. Founded by Klaus Perls in 1937 and operating until 1997, the gallery dealt primarily in modern French art and the artwork of Alexander Calder. Found within the records are extensive correspondence (circa 44 linear feet) with artists, dealers, galleries, museums, and collectors; photographs and negatives of inventory and other artwork; exhibition files, scattered financial records; and exhibition catalogs and clippings.

The Library of Congress Copyright Deposit Collection is comprised of 2,335 photomechanical reproductions of works by 741 artists (mostly American). The large-format prints, deposited with the Library of Congress for copyright between 1890 and 1945, represent a broad range of nineteenth- and twentieth-century American art.

The papers of New York artist, critic, historian, writer, art consultant and curator Walter Pach, measure 20.7 linear feet and date from 1857-1980. The collection documents Pach's promotion of modernism through his role in the landmark 1913 Armory Show, his relationships with artists and art-world figures and his extensive writings on art. Records include biographical material, correspondence with family, friends and colleagues including noted artists, handwritten and edited versions of manuscripts by Pach, diaries and journals, business records, printed material, scrapbooks, sketchbooks and artwork by Pach and others, and photographs of Pach and his family, friends, and colleagues. The collection also includes 12 linear feet of selections from Walter Pach's library.

The records of the Downtown Gallery date from 1824 to 1974 (bulk 1926-1969) and measure 109.56 linear feet. The records present a comprehensive portrait of a significant commercial gallery that operated as a successful business for more than forty years, representing major contemporary American artists and engendering appreciation for early American folk art. There is an unprocessed addition to this collection dating circa 1970 of a single financial/legal document.

This collection contains over 37,000 35mm slides, 3,000 glass lantern slides and garden files that may include descriptive information, photocopied articles (from journals, newspapers, or books), planting lists, correspondence, brochures, landscape plans and drawings. Garden files were compiled by Garden Club of America (GCA) members for most of the gardens included in the collection. Some gardens have been photographed over the course of several decades; others only have images from a single point in time. In addition to images of American gardens, there are glass lantern slides of the New York Flower Show (1941-1951) and trips that GCA members took to other countries, including Mexico (1937), Italy, Spain, Japan (1935), France (1936), England (1929), and Scotland. A number of the slides are copies of historic images from outside repositories including horticultural and historical societies or from horticultural books and publications. The GCA made a concerted effort in the mid-1980s to acquire these images in order to increase its documentation of American garden history. Because of copyright considerations, use of these particular images may be restricted.