The papers consist of correspondence, diaries, journals, financial records, writings, lectures, reproductions of sketches and documents which detail the lives of three generations of the Peale family. Material relating to the Peale Museum is also included.

The approximately 3,700 color and black and white drawings were collected and drawn by John Lawrence LeConte, with two in the first volume are by Titian R. Peale, but most are likely by John Abbot. The previous description noted that there are some drawings by John Abbot, and that most were likely by John Lawrence Le Conte. However, John V. Calhoun has shown extensive evidence that most of the drawings are by John Abbot (John Abbot's "Lost" Drawings for John E. LeConte in the American Philosophical Society Library, Philadelphia. Journal of the Lepidopterists' Society 60(4), 2006, 211-217). The contents of the collection: 1. Coleoptera. 654 figures. 2. Diptera, Hemiptera, and Lepidoptera. 564 figures. 3. Coleoptera. 698 figures. 4. Coleoptera and Hymenoptera. 228 figures. 5. Coleoptera. 657 figures. 6. Hymenoptera and Diptera. 234 figures 7. Diptera. 304 figures. 8. Hemiptera, Araneina, Myripoda. 356 figures