Containing over 4 linear feet of letters and documents, the Franklin-Bache Papers comprises the second largest collection of letters and documents relating to Benjamin Franklin in the APS Library. Although the scope of the collection is broad, including materials from the time of Franklin's arrival in Philadelphia to his death, the heart of the collection documents the period of Franklin's ministry in France (1776-1785) and his diplomatic efforts to win financial and military support for the revolutionary cause, as well as less intensive coverage of his ministry in England before the Revolution. Franklin's correspondence with American and French officials, financiers (personal and otherwise), and savants provides tantalizing details on the social context of Franklin's ministry in France, his intellectual life, and his growing celebrity. Much of the correspondence documents the efforts to convince French officials early in the war to support the American cause, but there is valuable material relating to the peace negotiations as well. The collection is equally rich in personal correspondence, including a rich set of letters from Mary Stevenson Hewson, Georgiana Shipley, Catherine Ray Greene, Jane Mecom, Deborah Franklin, and a number of Franklin's other relatives. The collection is arranged chronologically.

Founded in 1743 by Benjamin Franklin, the American Philosophical Society was the first learned society in the United States. For over 250 years, the Society has played an important role in American cultural and intellectual life. Until the mid-nineteenth century, the Society fulfilled the role of a national academy of science, national library and museum, and even patent office. Early members of the Society included Thomas Jefferson, David Rittenhouse, Benjamin Rush, Stephen Peter Du Ponceau, George Washington, and many other figures prominent in American history. The Archives of the American Philosophical Society consists of 192.25 linear feet of material, organized into thirteen record groups dating back to 1743. The Society's archives extensively documents not only the organization's historical development but also its role in American history and the history of science and technology.