The George A. Plimpton Papers consist largely of personal and professional correspondence, financial and real estate records, personal diaries and albums, writings, and lectures produced by or for George Arthur Plimpton. But the Papers also contains not only the correspondence and records of Plimpton's colleagues at Ginn and Company, the publishing house that Plimpton led for decades, but also correspondence and records relating to the dozens of other institutions and organizations that Plimpton helped lead. In addition to extensive correspondence relating to Plimpton's collecting of rare books, manuscripts, and historical artifacts, the Papers also contain such diverse items as autographs of presidents, handwriting specimens, studies of medieval manuscripts, and documents relating to the American slave trade.

The Plimpton Family Papers is primarily comprised of correspondence, personal and professional documents, writings and photographs generated by or for George Arthur Plimpton and Frances Taylor Pearsons Plimpton, their son, Francis T.P. Plimpton, and his wife Pauline Ames Plimpton. Also included are documents and photographs produced by or for other Plimpton, Pearsons and Ames family members, from seventeenth century ancestors to late-twentieth century descendants.