This collection includes letters between Ingenhousz and European and American scientists.

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.

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.

The Thomas Jefferson papers contain a large number of correspondence both to and from Jefferson, as well as various other material related to American Revolutionary War and Early Republic. Includes correspondence with Patrick Henry, Charles Willson Peale, Richard Henry Lee, Horatio Gates, David Rittenhouse, Robert Patterson