These papers related to Benjamin Franklin and the American Philosophical Society, and include correspondence among Benjamin Franklin, William Franklin, Jonathan Williams, Sr., and Jonathan Williams, Jr. Also included is Williams' journal of a trip through England with Benjamin Franklin, Jan Ingenhousz, and John Canton (1771), memoranda and essays by Williams on trade, meteorology, and sugar refining, and notes and drawings.

Since publication of I. Minis Hays's Calendar of the Papers of Benjamin Franklin in 1908, the APS Library has acquired a large number of miscellaneous letters and other documents relating to the life, mind, and work of Franklin and his immediate family. The collections listed in this finding aid consist of letters and documents to and from Franklin organized into groupings based upon provenance or focal point. The largest grouping consists of miscellaneous materials acquired individually or in small groups over the years, including a number of important individual items. The other collections consist largely of correspondence between Franklin and individual friends and colleagues, including his friends Mme Brillon, Mary "Polly" Stevenson Hewson, and Catherine Ray Greene, the Whig agriculturist Richard Jackson, and the printer Francis Childs. The collections include photostats of selected materials held by other institutions or that were in private hands. These are available for reference only.