The Fiske-Seymour Family Papers are separated into three series: Series I: Correspondence, Series II: Photographs, and Series III: Family Papers and Ephemera. The first series contains around 600 letters written by various members of the Fiske and Seymour families, as well as family friends. The bulk of the letters were written by William W. Fiske (over 200 letters) and Lida S. Fiske (over 100 letters). Many of these letters were written before Lida and William were married, and many of them were written while William was traveling for his job. Other substantial writers were Fleda F. Ochsner and Lucretia R. Seymour, writing over 50 letters each. The Family Correspondence folders contain letters written by family and friends that do not exceed more than two or three in number by each individual.

The collection also contains over 30 photographs of family members, as well as family-owned properties. Most of the photographs are undated. The Family Papers and Ephemera series contains newspaper and magazine clippings (some written by family members), programs for various events, school papers, and calling cards.