A collection of unrelated papers, linked by the family connections of the major figures. The papers of David Humphreys, a diplomat in the service of the United States, document his activities in Spain, 1789-1808. Also included are personal papers including correspondence with David Bushnell and Ezra Lee about submarines and with James Madison on politics, and some family correspondence. The papers of George William Erving, who was chargé d'affaires in Madrid (1804-1809) during Humphreys' tenure, complement the Humphreys diplomatic papers. The Marvin and Lemuel Gregory Olmstead (also Olmsted) families are represented by correspondence concerning life in New York and Connecticut in the 19th century. Of particular interest is a series of some sixty letters from Sarah Lucy Olmstead to her father describing her life in Erie, Pennsylvania from 1860-1865. Also in this part of the collection is a family photograph album and a journal kept by Lemuel Gregory Olmstead of his travels in New York State during 1830.