These papers include letters, reports, accounts, and memoranda relating to the work of the American Board of Home Missions among the Abnaki, Cherokee, Chickasaw, Choctaw, Creek, Dakota, Mackinaw, Maumee, Mayhaw, Ojibwa, Osage, Pawnee, Penobscot, Sioux, and Stockbridge Indians of Arkansas, New York, and Oregon.

This collection includes three journals bound into one volume: two by Willima Dunbar and one by Zebulon Pike. Both manuscripts by William Dunbar document the expedition up the Red and Ouachita Rivers to the Hot Springs of Arkansas in 1804-1805. The "Journal... to the Mouth of the Red River" (200p.) is the fullest available record of the activities of the expedition from the time of their departure from St. Catharine's Landing on October 16, 1804, until their return to Natchez, Miss., on January 26, 1805. The "Journal of a geometrical survey" includes a record of course and distances as well as a thermometrical log and other brief notes. The two are bound together in a volume with Zebulon Montgomery Pike's journal of a voyage to the source of the Mississippi, 1805-1806. The Pike journal documents the expedition to explore the geography of the Mississippi River led by Lt. Zebulon Montgomery Pike in 1805-1806, and his attempts to purchase sites from the Dakota Indians for future military posts, and to bring influential chiefs back to St. Louis for talks. Less a literary masterpiece than a straightforward record in terse military prose, the journal provides a day by day account of the journey and the activities of Pike and his small contingent during this early exploration of present day Minnesota. It was printed with variations and omissions in An Account of Expeditions to the Sources of the Mississippi and through the Western Parts of Louisiana... (Philadelphia, 1810), and was edited in Donald Jackson, ed., The Journals of Zebulon Pike: with Letters and Related Documents (Norman, Okla., 1966).

Though less well known than their peers Lewis and Clark, William Dunbar and George Hunter played an important role in the early scientific exploration of the Louisiana Purchase. While the original goal of organizing a southern counterpart to the Corps of Discovery proved overly ambitious, Dunbar and Hunter provided important geographic information for future explorations and gave the first scientific description of the Hot Springs of Arkansas and Ouachita Mountains. The four surviving journals of George Hunter provide engaging accounts of travel in the Ohio and Mississippi Valley in 1796, 1802, and 1809, and include the most interesting record of the expedition to the Hot Springs of Arkansas in 1804-1805, complete with his detailed notes on natural history and meteorology. The volumes also contain various references to relations with the Delaware, Chickasaw, Choctaw, Cherokee, and Osage Indians. The APS owns a contemporary copy of Hunter's journal ("Journal up the Red and Washita Rivers with William Dunbar"; Mss.917.6.Ex7), from which extracts were printed in Thomas Jefferson, Message... Communicating Discoveries Made in Exploring the Missouri (New York, 1806), and which is described by Isaac J. Cox, "An Early Explorer of the Louisiana Purchase," APS Library Bulletin 1946: 73. The journals were edited by John F. McDermott and published in APS Transactions 53 (1963).

The correspondence is principally to Zaccheus Collins (1810-1840), with bills, receipts, and notes on Rafinesque vs. Parker; letters from Collins, L.A. Tarascon, Lewis C. Beck, John Torrey, and Charles W. Short (1817-1835); and miscellaneous correspondence and documents relating to Rafinesque vs. Parker, with an account of the Felician Society of Feliciana County, Illinois (1820). The writings are chiefly on botanical topics, and include notes and essays on Indians, Blacks, grapes and wine-making, banking, and speculation. Rafinesque's growing interest in Indian antiquities, linguistics, and history is apparent in letters after 1820. There is an account of Rafinesque's scientific travels in North America and southern Europe (1800-1832), and a bibliography. The botanical notes include descriptions of specimens collected by Lewis and Clark, Patrick Gass, and Henry Muhlenberg.