Zebulon Montgomery Pike (1779-1813) was an explorer and soldier, most often remembered two exploratory trips to the newly acquired Louisiana territory. The first of these trips was to the source of the Mississippi River in 1805; the second was to explore the headwaters of the Arkansas and Red Rivers in 1806. Because General James Wilkinson was responsible for organizing Pike's two expeditions, when the conspiracy charges again Aaron Burr implicated Wilkinson, suspicion was, for a short time, also focused on Pike. Pike worked his way up the ranks of the United States Army, becoming a brigadier-general during the War of 1812. He was killed in the Battle of York in Upper Canada (now Toronto) in 1813.

This item is Lewis' narrative journal of the river trip from Pittsburgh to the winter camp of the Lewis and Clark Expedition, together with meteorological observations. There are also entries by William Clark. Of the 126 leaves in this journal, 31 contain questions by Nicholas Biddle, with William Clark's replies, dated 1810. Includes parts II and III of Nicholas Biddle, "Notes on Indians...", and list of measurements of bones and other natural history specimens, in Lewis' hand. Also contains some sketches and two small maps.

Benjamin Edwards was a minor figure on the Stephen H. Long Expedition to the Rocky Mountains. His six letters addressed to his father Oliver Edwards briefly mention the expedition, including his attempts to collect pay for his part in the expedition. His letters also discuss his life in Louisiana after the expedition working on the Steamboat Hope and later as overseer of slaves in a sawmill.

This diary is a journal of a trip from Philadelphia by stage to Pittsburgh, then afoot through Franklin, LeBoeuf, and Erie to the Huron River; thence by boat to Detroit, where he remained 26-29 July, when he set out by canoe for Michilimackinac. Included are descriptions of Detroit, plants, animals, springs, Indian mounds, and notes on goitre.

This item is a detailed description of the geography, population, natural resources, and agriculture of the Ouachita River area of the Louisiana Territory. Describes mounds; mentions Cataoulou Indians; also gives figures as to numbers of white and Indian hunters. These pages are a record of travel on a road built between Choctaw and Chickasaw country, with comments on the condition of Indian-white relations, the increase in white population, and Wilson's stay, at Muscle Shoals, with Cherokee chiefs Doublehead and Skiowska. Wilson finds the Indians have good farms, furnishings, fences, and stock, and one Indian runs an inn.

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).

Through his craniometic studies of human races, the Philadelphia physician Samuel George Morton (1799-1851) exerted a profound influence on the development of physical anthropology in antebellum America, and made substantial contributions to mineralogy, paleontology, and natural history. Relating primarily to Morton's scientific interests, the Morton Papers include insights into Morton's perspectives on education, medical practice, geology and mineralogy, craniology, paleontology, the Wilkes Exploring Expedition (also known as the United States Exploring Expedition 1838-1842), and his two major monographs, the Crania Americana and Crania Aegyptiaca. Several of the letters were written by Morton in his capacity as corresponding secretary of the Academy of Natural Sciences of Philadelphia. Also included in this collection are Morton's "Some Remarks on the Infrequency of Mixed Offspring Between the European and Australian Races" (1850), Joseph Barclay Pentland's notes on the aborigines of Peru (ca. 1840?), and newspaper clippings on Morton's death; a diary of Morton's trip to the West Indies, 1834, a set of craniological sketches for use in Crania Americana, and a microfilm of letters in private hands, written to Morton, 1838-1844