The only son of Benjamin Franklin, William Franklin served as Royal Governor of New Jersey during the critical years between 1762 and 1776. An ardent Loyalist, William split with his father over their political differences in the early days of the Revolution, and after enduring two years of imprisonment, became a leader in the Loyalist cause. He settled in London in 1782, where he worked as an agent for Loyalist claims. The William Franklin Papers are a miscellaneous assemblage of letters and documents, dealing largely with Franklin's years as Royal Governor of New Jersey. The majority of the letters are perfunctory, however they provide some information on Franklin's land holdings in New Jersey and the Ohio country. The collection includes two letters relating to Franklin's imprisonment in Connecticut during the Revolution, two affectionate letters to his sister Sarah, and one to his son William Temple Franklin.

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.