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.

Two bound documents, "A chronological series of facts relative to Louisiana" and "An examination into the boundaries of Louisiana." Prepared by Jefferson for U.S. ministers at Paris and Madrid, as a means of determining the extent of the Louisiana Purchase. Jefferson sent these to the APS with a cover letter to Peter S. Du Ponceau, dated December 30, 1817; read in the Historical and Literary Committee, 1818. Printed in Thomas Jefferson, Documents Relating to the Purchase and Exploration of Louisiana (New York, 1904).

This collection consists almost entirely of letters, mostly written by Jefferson, to various people. The largest portion of the letters are from Jefferson to Louis Hue Girardin concerning the latter's work in completing The history of Virginia: from its first settlement to the present day, Volume 4 . Of particular interest is Jefferson's notes on his colleges' role in that history, including the plot to establish a dictator of Virginia. The letters to Girardin also include discussions of plants, the building of the University of Virginia, and books.

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.

These are primarily papers relating to the work of the United States Army Corps of Topographical Engineers, with special reference to surveys of harbors of the eastern United States. Some papers and letters relate to natural history and are addressed to John Lawrence LeConte. Correspondents include Rutherford B. Hayes, Joseph Henry, Daniel Parker, and E.G. Squier.

This collection contains mostly entomological material, with much information on the description and identification of particular insects, entomological collections, and the study of entomology in Europe and the United States. In addition, there are materials on medicine and hospitals during the American Civil War, on the Corps of Topographical Engineers, the United States Army, on natural history in the United States, and on the LeConte's family. Some letters are written to President Rutherford B. Hayes and concern the Commissionership of Agriculture, for which LeConte was considered, but not appointed. Letters of John Eatton LeConte and Joseph LeConte are included.

The most stellar member of a stellar family, Elisha Kent Kane was among the most popular American explorers of the mid-nineteenth century, a hero in the tragic mode. Born in Philadelphia in 1820, the son of John Kintzing Kane and Jane Duval Leiper, Kane studied medicine at the University of Pennsylvania before earning a commission as a naval surgeon. While in the Navy, Kane embarked on the succession of voyages to exotic locales that became the basis for his extraordinary fame. In 1843, he attended Caleb Cushing's first diplomatic mission to China as ship's physician, and subsequently traveled to the Philippines and Western Africa. Distinguishing himself in the Mexican War, Kane's greatest fame came from two expeditions to the arctic, aiming to locate the lost explorer, Sir John Franklin and to explore for evidence of the open polar sea. Kane died in 1857 while attempting to organize a third arctic voyage. Part of the Kane Family Collection, the Papers of Elisha Kent Kane contain a mix of personal and family correspondence with correspondence relating to all of Kane's explorations. Intelligent, articulate and very much a romantic, Kane's letters are expressive and passionate. The collection provides fine documentation of youth, his relationship with the Spiritualist Margaret Fox, and of course his travels to China and off the coast of Africa in 1846. Kane's two expeditions to the arctic are particularly well documented, with correspondence, notes, logbooks, diaries, and sketches, as well as Kane's post-expedition notes, writings, and lectures recounting his experiences.

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

George Ord made important contributions as an ornithologist and writer but is also famous for his contempt of fellow ornithologist John James Audubon. Throughout his life he published numerous scientific articles and assisted in completing Alexander Wilson's life's work, American Ornithology; or, The Natural History of the Birds of the United States. Ord also left his mark as a member of the American Philosophical Society and as the president of the Academy of Natural Science of Philadelphia. The George Ord collection consists primarily of outgoing personal correspondence to Charles Waterton ranging from 1831 to 1866 that highlights Ord's professional as well as personal affairs, most notably his hostility toward Audubon. The collection is supplemented by correspondence of Ord's to and from various individuals regarding personal and business matters.