Gertrude Ruhnka (1891-1981) was a research librarian at the Huntington Library in California. The collection contains her unpublished manuscript, "Love for life: a self-portrait of the first three generations of du Ponts in America, 1791-1834," and two letters from Ruhnka to J.B. Lippincott Company and Dr. Walter J. Heacock of the Eleutherian Mills-Hagley Foundation.

Pierre Samuel du Pont de Nemours (1739-1817) was a French political economist, writer, publisher, and public administrator. His son, Eleuthère Irénée du Pont (1771-1834), established E.I. du Pont de Nemours & Co., a black powder manufacturer, on the Brandywine River in Delaware. The collection contains photocopies of three letters of du Pont de Nemours du Pont to Etienne Alexandre Jacques Anisson du Perron (1749-1794) and Alexandre Brongniart (1770-1847). The letters concern printing, natural sciences, and requesting scientific journals and bulletins.

Pierre Samuel du Pont de Nemours (1739-1817) was a French political economist, writer, publisher, and public administrator. In 1800, accompanied by his sons, Victor Marie du Pont (1767-1827) and Eleuthère Irénée "E.I." du Pont (1771-1834), he arrived in America. In 1802, E.I. du Pont established E.I. du Pont de Nemours & Company, which began manufacturing gunpowder. This item is a letter written to President Thomas Jefferson about du Pont de Nemours' son, E.I. du Pont, as a gunpowder manufacturer and requesting Jefferson's opinon on the matter of refining saltpetre.