Letters (including some transcripts and photostats) from and to Vaughan from many American and British correspondents, including: Also personal correspondence and business papers of Benjamin, Charles, Petty, Samuel Sr., Samuel Jr., William, William Oliver, and Sarah Vaughan (2 boxes); lectures, mostly in shorthand (3 vols.); a large number of notes and memoranda on a wide variety of topics, such as agriculture, architecture, astronomy, diplomacy, diseases, dueling, electricity, hieroglyphs, internal improvements, medicine, meteorology, land, manufactures, politics, punctuation, religion, silk-manufacturing, stock-breeding, taxation, Unitarianism, Benjamin Franklin, John Locke, Napoleon I, Joseph Priestley, Bowdoin College, town of Hallowell, Maine; notes on the peace negotiations, 1782-1783; miscellaneous legal papers; genealogy of the Abbott-Vaughan families. For a personal account of the collection, see Mrs. Mary Vaughan Marvin, "The Benjamin Vaughan Papers," APS Proceedings 95 (1951): 246-249.

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.

One of the oldest houses in Philadelphia, Wyck is now a non-profit museum listed on the National Register of Historic Places. Nine generations of the Jansen-Wistar-Haines family owned the Wyck property from 1690 until 1973. The last family owner deeded 2.5 acres of land, the house and its contents, several outbuildings, a landscaped garden, and a small endowment to the Wyck Charitable Trust. The Wyck Charitable Trust and the Wyck Association now administer the preservation of the property and its educational services to the public. This collection contains diaries, letters, accounts, bills and receipts, deeds, and photographs. The collection as a whole is deepest for the period 1770-1970. Items of particular note include accounts of household expenses at Wyck from ca. 1790-1970; papers pertaining to the Academy of Natural Sciences of Philadelphia, Quaker schools, and social reform groups; agricultural and horticultural practices; and correspondence to and from cultural leaders of 18th and 19th century Philadelphia. The papers of the John S. Haines family (Ms. Coll. 52A) form part of the Wyck Papers. The papers cover the years 1845 to 1949 and are arranged into eight series.

Personal and professional correspondence of the chemist Robert Hare, including drafts of letters to editors of journals on such varied topics as fish guano, slaughterhouses, paper money, and the meaning of the term "Yankee annexations." The collection originally contained over 300 scrolls, since disbound, which contained drafts of letters, essays, and lectures, composed by Hare on ordinary sheets of paper, then pasted end to end, and rolled up. The essay and lecture topics include: chemistry, storms, slavery, currency, fire-fighting, capital punishment, railroads, the Smithsonian Institution, Michael Faraday, religion and Spiritualism, riots in Philadelphia, epidemics, underwater blasting, and Ralph W. Emerson; there is some verse. The collection also contains an account book of Hare and his wife, 1806-1829 (180 pp.; B/H22#3); a volume by Hare on Cyclones (tornadoes), n.d. (ca. 60 pp.; B/H22#4); and Samuel Powel, Jr.'s "Short notes on a course of antiquities at Rome... under M. Byre Antiquarian," 1764. (60 pp.).

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