- Autograph letters from members of the Bartram family. Two letters, both by John Bartram (1699-1777), are of particular interest: the first to Cadwallader Colden, describing his recent expedition up the Susquehanna River; the second to William Bartram, which begins "Dear Billy, I have now a most grievous cough that teaseth me night and day yet I have sent thee six likely young negroes among which is [sic] two young breeding wenches..." John Bartram was a prominent botanist who established a successful garden in Kingsessing, Pa. and led numerous expeditions throughout the Eastern United States.
- Three folders (62 items) of mostly official signed documents from Burnet's tenure as governor of New York and New Jersey, including land grants, warrants for letters patent, memorials, leases, receipts, bills, and lists of accounts. James Alexander is a frequent co-signer and correspondent, and the collection also includes several bonds from Alexander to Burnet for fairly large sums of money. A few later documents discuss the disposition of Burnet's estate., William Burnet served as governor of the colonies of New York and New Jersey from 1720-28, and as governor of the colony of Massachusetts from 1728-1729.