The Marshall family papers document to varying degrees of completeness the activity of five generations of Holmes, Marshall, DeAngelis and related families who settled early in central and western New York. The papers reveal primarily the internal workings of the family centered around Orsamus and Millicent Marshall: their attitudes and far-flung family relationships, their social position, the rearing of children and their growth, and the travels of and intellectual activities of family members. Other papers of interest are the records of the family legal firm, records and papers relating to the organizations and clubs in which members of the family played a part, and an eyewitness account of the Battle of Valcour Island on Lake Champlain, a naval battle of the War of 1812.

The family records contain a genealogy of the Cooper family from 1845 to 1956. It also contains the legal papers of the Gaylord family, including deeds, mortgages and business correspondence.