Letters and papers relating to Sparks's research on Benjamin Franklin and the publication of an edition of the latter's writings. There are also extracts from Sparks's journal, 1831-1841, relating to his Franklin researches.

This diary records the individuals and sights that he saw while in England. There are many observations of life in London, e.g. parks, buildings, paintings, food. Outside of London he visited many towns, including Manchester and its cotton mills as well as the steel mills of Birmingham. He relates his visit to Drury Lane and the dramatic performance of Sarah Siddons. Some of the people he met included Sir Joseph Banks, Sir Charles Blagden, Matthew Boulton, Joseph Priestley, William Pitt the Younger, and Benjamin Vaughan. He also visited and described the gardens at Kew. The diary includes several sketches, including the plan of Blenheim Palace, and also a table of distances traveled.

Correspondence of Joseph Priestley, scientist, Unitarian minister, and republican theorist. The collection includes 41 letters written to John Vaughan, 1791-1800, 5 letters to other correspondents, and manuscripts and photostats of 68 items in the Municipal Library, Warrington, England, on theological issues, the internal development of the United States, the French Revolution and its aftermath, Unitarianism, science, his publications, and American Philosophical Society.

These selected papers include correspondence concerning Franklin, Franklin's descendants, and Franklin's papers, extracts from Philadelphia newspapers on Franklin, papers used in Sparks' biography, miscellaneous entries in his diary (1830-1854) relating to his search for Franklin manuscripts, and his preparation of an edition of Franklin's writings. Correspondents include Henry Stevens, Jr.; Henry Stevens, Sr.; Benjamin Vaughan; Petty Vaughan; James Mease; H. D. Gilpin; J. Francis Fisher; Franklin Bache; and others.

This collection is comprised of materials from seven repositories and includes correspondence from Banks' colleagues and explorers, such as John Hope, Josiah Wedgwood, Georg Forster, and Captain William Bligh; records of expenses for voyages and journeys; and journals kept during voyages to New Foundland and Labrador (1766) and around the world with Captain James Cook (1768-1771). Topics include botany and horticulture, marine life, and collecting specimens.

Letters (including some transcripts and photostats) from and to Vaughan from many American and British correspondents, including: Also personal correspondence and business papers of Benjamin, Charles, Petty, Samuel Sr., Samuel Jr., William, William Oliver, and Sarah Vaughan (2 boxes); lectures, mostly in shorthand (3 vols.); a large number of notes and memoranda on a wide variety of topics, such as agriculture, architecture, astronomy, diplomacy, diseases, dueling, electricity, hieroglyphs, internal improvements, medicine, meteorology, land, manufactures, politics, punctuation, religion, silk-manufacturing, stock-breeding, taxation, Unitarianism, Benjamin Franklin, John Locke, Napoleon I, Joseph Priestley, Bowdoin College, town of Hallowell, Maine; notes on the peace negotiations, 1782-1783; miscellaneous legal papers; genealogy of the Abbott-Vaughan families. For a personal account of the collection, see Mrs. Mary Vaughan Marvin, "The Benjamin Vaughan Papers," APS Proceedings 95 (1951): 246-249.

This collection includes letters to and from Americans (including South America and the West Indies) and letters about America selected from the Society's manuscripts (Classified Papers, Letter Books, Letters and Papers, Royal Society Letters, Miscellaneous Correspondence, and other official groups) and from collections of private papers (Sir Charles Blagden, William Buckland, John Canton, Sir John F. W. Herschel, Sir Edward Sabine, and others). The documents range in time and character from John Winthrop, Jr., "A Description of the Artifice & Making of Tarr & Pitch in New England" (1662), to letters from Sir Thomas Edward Thorne to his wife describing the American West, where he was on a surveying party in the 1880s.