The American-Moninger Greenhouse Manufacturing Corporation Collection includes 306 architectural plans and drawings of greenhouses, solariums, conservatories, garages, and other structures designed by American-Moninger for clients throughout the United States dating from 1923 to 1964.

Correspondence, invoices, nursery and seed catalogs, estimates, planting plans, photocopies of blueprints, photographs, negatives, autochromes, and drawings relating to the gardens of The Chimneys, the home of Emma and Gardiner Martin Lane and their daughter Katharine Lane Weems in Manchester, Massachusetts. Also included are four garden journals (1903-1928), garden-related medals awarded to Emma Lane, index files of plant materials, photocopies of garden related library cards belonging to Gardiner M. Lane, a diascope and nursery and seed catalogs. The collection also includes architectural plans, invoices and specifications from, and a framed photograph of, Raleigh C. Gildersleeve, architect of The Chimneys and brother of Emma Lane.

The Hollerith Family Collection includes approximately 2,200 35mm slides dating from 1952 to 1980 that document the horticultural interests and travels of sisters Virginia and Nan Hollerith, members of the Georgetown Garden Club in Washington, D.C. The images primarily show private and public gardens, plantations, and historic sites in the mid-Atlantic and the southeast regions of the United States. Included in the collection are slides documenting the activities of the Georgetown Garden Club and various floral arrangements.

The Maida Babson Adams American Garden Collection documents the work of Molly Adams, a free-lance garden photographer who photographed hundreds of private and public gardens, many of them in the mid-Atlantic region, from the late 1950s through the mid-1990s. It includes slides, photographic prints, negatives and transparencies. A significant number of images document the work of landscape designers Nelva M. Weber, Alice Recknagel Ireys, and Friede Stege. Roughly 50 gardens do not have an identified location. Some images have captions and other information written on them.

The Thomas Warren Sears Photograph Collection documents examples of the design work of Thomas Warren Sears (1880-1966), a landscape architect and amateur photographer from Brookline, Massachusetts. Sears, who was based for most of his career in Philadelphia, designed a variety of different types of landscapes ranging from private residences, schools, and playgrounds to parks, cemeteries, and urban housing developments located primarily in Pennsylvania, Maryland, and New York. In addition to some of Sears' design work, images in the collection document Sears' domestic and foreign travels, design inspirations, and family. The collection includes over 4,800 black and white negatives and glass lantern slides dated circa 1899 to 1930. While most images show private and public gardens, there are a significant number of unidentified views and views photographed in Europe during two trips he took there in 1906 and 1908. Few images are captioned or dated. In addition, there are over 50 plans and drawings, most notably for Balmuckety in Pikesville, Maryland and Reynolda in Winston-Salem, North Carolina, and 3 monographs by or about Sears.

A collection of approximately 28,000 glass plate negatives showing views of a variety of subjects.

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.