The Mildred N. Beauregard Slide Collection contains 1,249 35mm slides, dated circa 1947-1971, of gardens and castles in England, Scotland, France, Holland, Switzerland, Sweden, Norway, and Denmark, as well as American gardens, photographed by Mildred Napier Beauregard. Some slides show tourist sites and scenes including skylines, rock features, waterways, boats and ships, and unidentified individuals. The collection also includes two slide viewers.

The Historic Gardens Postcard Collection includes 200 postcards of historic views of various public gardens, parks, monuments, and buildings throughout the United States and some foreign countries, including Canada, France and Cuba. Some private gardens and estates and many Washington, D.C. attractions are also represented. Roughly half of the postcards were mailed; the remaining postcards were not written on or posted. Areas represented include Arizona, California, Colorado, Delaware, Florida, Illinois, Indiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Nebraska, New Jersey, New York, Ohio, Oregon, Pennsylvania, Texas and Virginia. Foreign views show gardens in Havana, Paris, and Canada. About a dozen cards feature various views of Smithsonian Institution museums along the National Mall in Washington, D.C.

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.

The Captain A.H. McComb, Jr. Collection includes approximately 230 35mm slides of public and private gardens and landscapes dating from 1956 to 1966, photographed by Captain A.H. McComb, Jr. at sites in Washington, D.C., Maryland, Virginia, New York, United States Virgin Islands, Argentina, Bermuda, Capri, Cuba, Denmark, England, France, Germany, Haiti, Jamaica, Panama, Puerto Rico, and Tobago.

Photographs collected and made by Helen Hamilton Gardener, probably during a world cruise following her husband's retirement from active duty in Puerto Rico in July 1902. The photographs document people, activities, cities, and tourist sites in Japan, China, Egypt, France, Puerto Rico, and elsewhere. Gardener's lecture notes and a clipping from t...

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.

Sixteen photographs and glass negatives (ca. 1889-1909), possibly taken by Perry on her trips to Giverny, show Claude Monet and his house, studio, and garden at Giverny, France.

The William Lyman Phillips Collection includes thirty glass negatives and two glass autochromes showing a sampling of gardens presumably designed by landscape architect William Lyman Phillips. The gardens are located in Massachusetts, Florida and unidentified locations.

The Boris V. Timchenko collection includes project files, business records, and personal papers of Boris Timchenko, a modernist landscape architect based in the Washington, D.C. metropolitan area known for his work on The Watergate Development and the annual National Capital Flower and Garden Show.

The American gardens collection, a component of the Archives of American Gardens (AAG), includes holdings not associated with other major collections in the archives. The slides, photographs, plans, and files in this collection come from various private donors. Individual sub-units typically depict a single garden.