In October 1719, the Yearly Meeting of the Society of Friends for Philadelphia and the Jersies reached consensus on a "book of discipline" governing the "establishment and order of meetings." The regulations covered both the conduct of the Quarterly and Monthly Meetings and the personal comportment of individual members, refining the bureaucratic structure of the meetings and laying out the powers of Overseers and other officials. It touches upon marriage (mandating endogamy), burial, and attendance at meetings, and cautions Friends to plainness of speech and dress, drinking, smoking, backbiting, and gaming. This version of the Book of Discipline is a manuscript copy made for the American Philosophical Society in 1820 "from and antient Copy in the possession of Timothy Matlack, Esqr."

The Welsh non-conformist minister Richard Price (1723-1791) was a moral philosopher and political and economic theorist whose ideas leant support to the American cause during the Revolution. Of broad and liberal mind, he was an integral member of the intellectual coterie surrounding William Petty, the Earl of Shelburne, and was a founding member of the Unitarian Church. Befitting a latitudinarian thinker, the range of Richard Price's correspondence is extremely broad, touching upon his rationalistic philosophy and dissenting theology, his political views on British politics, America and the American Revolution, the Constitutional settlement, the future of the United States, social reform, demography, prisons, and slavery. The ninety letters in the collection are arranged chronologically, with correspondents including Charles Chauncy (8 letters, 1772-1779), Benjamin Franklin (7 letters, 1775-1789), John Howard (11 letters and a biographical manuscript, 1770-1789), Thomas Jefferson (3 letters, 1785-1789), Benjamin Rush (8 letters, 1786-1790), and Edward Wigglesworth (3 letters, 1775-1786), as well as lesser known figures such as the reformer John Howard.

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.

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.).

The Anthony F. C. Wallace Papers include correspondence to and from 20th century anthropologists, ethnologists, historians, linguists, and psychiatrists and provides a wealth of resources for the study of technological and social change, American Indians, culture and personality, revitalization movements, the anthropological study of religion, and the cultural and biological bases of behavior. In addition to Wallace's correspondence, research notes, and drafts, the collection includes Wallace family correspondence and photographs, as well as Wallace's writings from childhood through recent years.