Alfred Victor du Pont (1900-1970) was a partner in the Wilmington, Delaware, architectural firm of Massena and Du Pont, and he was the third child of Alfred I. du Pont (1864-1935) and his first wife Bessie Gardner du Pont (1864–1949). This small collection includes both business and personal papers. The largest portion is made up of Alfred V. du Pont's correspondence with his father, Alfred I. du Pont.

Alice Belin du Pont (1872-1944) was a member of several social clubs and became very involved with philanthropic work. She was the daughter of Henry Belin Jr. (1843-1918) and Margaretta Lammot Belin (1846-1927), and wife of Pierre S. du Pont (1870-1954). The letter is from du Pont to Haynes Battan (1898-1979), a Longwood employee.

Consists of the family papers of former DuPont CEO Lammot du Pont Copeland (1905-1983) and his wife Pamela Cunningham Copeland (1906-2001). The Copelands' papers document the lives and interests of a wealthy American couple in the twentieth century. In particular, the papers of Pamela C. Copeland are an important source of information about the public activities of women in the areas of historic preservation, gardening and horticulture, and philanthropy.

Louise du Pont Crowninshield (1877-1958) was an early leader in the field of historic preservation and a collector of antiques and hooked rugs. The collection includes her papers as well as those of her husband Francis Boardman Crowninshield, her mother, and other family members.

Louise Evelina du Pont (1877-1958) was an heiress and preservationist, who was the great granddaughter of Eleuthère Irénée du Pont (1771–1834), the founder of E. I. du Pont de Nemours and Company. She was the last du Pont to live on the Eleutherian Mills estate. This collection consists of photographic and graphic materials primarily of Crowninshield's extended du Pont family and friends. The collection has been organized into four series: Family portraits, Travel photographs, Residences, and Mary Pauline Foster du Pont sketches and collection of travel souveniers.

Victorine Elizabeth du Pont Foster (1849-1934), daughter of Henry du Pont (1812-1889) and Louisa Gerhard du Pont (1816-1900), grew up at Eleutherian Mills, near Wilmington, Delaware. The drawing is a detailed plan of the formal garden at Eleutherian Mills. Placement of trees, flowers, and vines, etc., are indicated on the drawing.

T. Coleman (Thomas Coleman) du Pont (1863-1930) was President of the DuPont Company from 1902 to 1915, and a U.S. Senator from Delaware from 1921 to 1928. He married Alice du Pont (1863-1937) in 1891. The "Old Mill" was constructed in 1909 to 1910 as a weekend home for T. Coleman du Pont in an area near Greenville, Delaware. These photographs document the Old Mill, retreat of T. Coleman du Pont, and the surrounding gardens planted by his wife, Alice.

Victorine du Pont Foster (1849-1934) was the granddaughter of Eleuthère Irénée "E.I." du Pont (1771-1834) who founded the E.I. du Pont de Nemours & Company, a chemical company which began with the production of gunpowder. Her husband was Antoine Foster (1847-1928). The collection contains a typescript of Foster's memoir, "A Lost Garden" which describes the former garden at Eleutherian Mills.