Born May 26, 1750, to the niece of Benjamin Franklin, Jonathan Williams was a prominent merchant, scientist and soldier. Elected to the APS in 1787 as a result of his observations on temperature and barometrical readings, as well as work on sugar production, Williams had a distinguished military career highlighted by his appointment as first superintendent of the Military Academy at West Point. The Jonathan Williams Papers consists of 46 letters and documents, written by or to Jonathan Williams Sr. and Jr., dealing primarily with financial and legal matters. The collection includes five letters written by Benjamin Franklin and many of the others are signed by Williams' father-in-law and brother-in-law, William and Robert Alexander.

The Calendar of the Papers of Benjamin Franklin prepared by Isaac Minis Hays for the bicentennial of Franklin's birth in 1906 provides access to the largest portion of the Franklin Papers at the APS. The items were originally bound into volumes in roughly chronological order, with letters to Franklin preceding those from Franklin and at the end of the collection, Franklin's letters owned by the University of Pennsylvania. Each manuscript is still identified by Hays' reference numbers, which include a roman numeral refering to the original volume followed by an arabic number to identify the folio. The electronic version of the finding aid replicates Hays' calendar, including the introductory material and item-level descriptions. It has been updated to reflect corrections in the metadata, corrections of personal names, dates, and description.