Series I. Burnham Family Papers includes six subseries, each comprised of materials from a different family member.

Subseries A. Albion Burnham Papers document Albion's years as shipmate on the Southern Cross (Ship), which was captured by the Florida (Confederate States Steamship) in 1863; on the Carnation (United States Steamship) during the remainder of the Civil War; and on the Abbie Bursley (Schooner). Other materials include photographs of Albion in uniform, documentation on Civil War pensions, logbooks, cash account books, cargo receipts, medals, and hair samples from around the world. Personal papers include receipts for ordinary living expenses and correspondence between Albion, his brother Everett Burnham, and his nephew Robert Burnham.

Subseries B. Everett Burnham Papers contain correspondence, school papers, yearly diaries and receipts.

Subseries C. Ida Angier Burnham Papers contain school papers, a diary, correspondence from a niece in Europe, and receipts.

Subseries D. Robert Burnham Papers include personal records such as correspondence, school papers, and receipts, as well as performance programs, pamphlets, and articles related to his career as an impersonator, drama teacher, and entertainer. A scrapbook of career-related clippings and photographs is also included.

Subseries E. Deacon Samuel Burnham Papers include a professional award as well as correspondence from Samuel while he was a student at Phillips Academy, Andover, Massachusetts from 1839-1842.

Subseries F. Captain Samuel Burnham and Sally Andrews Burnham Papers include professional and legal papers, correspondence, account books, and estate materials.

Subseries G. Miscellaneous is comprised of song lyrics, poems, concert and theater programs, and pamphlets. Newspaper clippings, ranging in years from 1846 to 1925, provide information about the Burnhams, shipbuilding, and the maritime industry. This subseries also includes the wills, diaries and writings of other members of the Burnham family, including Willis Burnham, Clarence Burnham, Choate Burnham, and Eliza Mills.