These are letters of Mary Stevenson Hewson to her mother-in-law, sister-in-law, and children, and their letters to her. Of special note are the letters from Thomas Tickell Hewson in London and Edinburgh. There are also letters and papers of William Hewson, including letters from Anthony Fothergill, John Morgan, and Williams Smibert, and letters about Mary Stevenson Hewson's estate. There are many references to Benjamin Franklin, Benjamin Franklin Bache, Jonathan Williams, John Hawkesworth, and others.

Nine of these letters are addressed to Sir Alexander Dick of Edinburgh (1763-1768), and relate to Morgan's medical studies, his travels on the Continent, and the founding of the medical department of the College of Physicians. These are copies of originals in possession of Mrs. Dick Cunyngham, Prestonfield House, Edinburgh. In addition there are letters from Morgan to: Petrus Camper, William Smith, Samuel Vaughan, Jr.; and from Peter Collinson to Camper; Camper to Morgan; S. Vaughan Jr. to Camper; and an exchange between Christian F. Michaelis and Camper. These concern Morgan, with mentions of fossils (mastodon bones in America), natural history, comments on Franklin, Jefferson, and Angelica Kauffmann. These are from originals in the Petrus Camper Papers, on deposit (1976) at the University of Amsterdam Library.

In addition to the College of Philadelphia, the city prison, and uncounted widows, the firm's customers included many prominent Philadelphians. Contains account B. Franklin [p. 122], et al.