Henry Algernon du Pont (1838-1926) was a military officer, a politician from Delaware, and vice president of E.I. du Pont de Nemours & Co. The collection consists of five letters from du Pont to Gustav Schelle (1845-1927) and one from Schelle. The letters mostly express personal friendship and deal indirectly with Schelle's writings on the Physiocraps and du Pont de Nemours.

Pierre Samuel du Pont de Nemours (1739-1817) was a French political economist, writer, publisher, and public administrator. He was an advocate for a national educational system and promoted Franco-American trade relations. The collection consists of Pierre Samuel du Pont de Nemours correspondence and writings in addition to correspondence of his second wife, Françoise (Robin) Poivre.

Pierre Samuel "P.S." du Pont (1870-1954) was an industrialist, entrepreneur, and philanthropist. He was president of E.I. du Pont de Nemours & Company from 1915 to 1919 and chairman of the board of directors from 1919 to 1940. P.S. du Pont was the great-grandson of Eleuthère Irénée du Pont (1771-1834), founder of E.I. du Pont de Nemours & Company, and the great-great-grandson and namesake of the French economist Pierre Samuel du Pont de Nemours (1739-1817). During the early 1920s, P.S. du Pont became an active collector of Du Pont materials, and bought several important bodies of manuscripts from French dealers. This collection consists of manuscripts he collected that are primarily concerned with Du Pont de Nemours, the Physiocrats, the French Revolution, and the antecedents of the Du Ponts and allied families in France. The collection also contains the Wilmington & Kennett Turnpike Co. records dating from 1811 to 1921 that were acquired by P.S. du Pont from 1919 to 1920 when he purchased the company's stock, widened the road, and turned over its administration to the Delaware State Highway Department.