Founded in 1743 by Benjamin Franklin, the American Philosophical Society was the first learned society in the United States. For over 250 years, the Society has played an important role in American cultural and intellectual life. Until the mid-nineteenth century, the Society fulfilled the role of a national academy of science, national library and museum, and even patent office. Early members of the Society included Thomas Jefferson, David Rittenhouse, Benjamin Rush, Stephen Peter Du Ponceau, George Washington, and many other figures prominent in American history. The Archives of the American Philosophical Society consists of 192.25 linear feet of material, organized into thirteen record groups dating back to 1743. The Society's archives extensively documents not only the organization's historical development but also its role in American history and the history of science and technology.

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