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.

These documents are principally of Pennsylvania interest, 1757-1809, including letters to Richard I. Manning from John C. Calhoun, Marquis de Lafayette, George McDuffie, and William Wirt. There are also letters of Clement C. Biddle, James Buchanan, Francis J. Grund, James Madison, Timothy Pickering, and William H. Seward. In addition, there are several musical scores (n.d.) and 19 cancelled checks (1861-1871) drawn by Ticknor and Fields in Boston, to the order of various American authors.

An extensive family collection, the Vaux Family Papers center around the lives of George Vaux V (1721-1803), George Vaux VII (1779-1836), and George Vaux VIII (1832-1915), their business partners, siblings, wives, and children, and encompasses the extended Vaux family of Warders, Sansoms, Heads, Graffs, Morrises, Cressons, and Mayberrys. The collection includes correspondence, financial accounts, receipts, business records, journals, diaries, photographs, and legal documents.

An early settler and prominent citizen in the Moravian heartland near Bethlehem, Pennsylvania, Timothy Horsfield was named justice of the peace when Northampton County was formed out of Bucks in 1752, and was one of those given responsibility for the defence of the local white and Christian Indian populations during the French and Indian War. The Horsfield Papers offer a window onto the tumultuous history of northeastern Pennsylvania during the 1750s and 1760s. Comprised largely of correspondence and related documents between Horsfield, William Parsons, and provincial and military authorities, the collection includes important information on the Native tribes' actions (previously described as "Indian assaults") in the region in 1756 and 1757 and the military and diplomatic response of settlers.

Robert Maskell Patterson (1787-1854, APS 1809) was a professor of chemistry and natural philosophy at the University of Pennsylvania (1812-1828) and professor of natural philosophy at the University of Virginia (1828-1835). He was director of the U.S. Mint from 1835 to 1851. His father, Robert Patterson, was a revolutionary soldier, professor of mathematics at the University of Pennsylvania (1779-1814), and director of the U.S. Mint (1805-1824).

A Sachem and Civil War adjutant to Ulysses Grant, Ely Samuel Parker was an important figure in the Seneca Indian nation during the first half of the nineteenth century. Trained as an engineer, Parker was deeply involved in the Senecas' land disputes with the Ogden Land Company and he played an important role in interpreting Seneca culture for a white audience, most notably as a consultant for Lewis Henry Morgan. Collected by Arthur C. Parker, the Ely Samuel Parker Papers include correspondence, manuscripts, and printed materials relating primarily to Seneca affairs, history, language, and culture, as well as politics, education, engineering, and the Civil War. Among Parker's correspondents were Henry Clay, Millard Fillmore, Henry M. Flagler, Lewis Henry Morgan, Henry Rowe Schoolcraft, Daniel Webster, and Asher Wright. Several letters relate to Parker's service as engineer of public buildings in Galena, Illinois, and to his Masonic activities. Among the noteworthy items in the collection are several essays on Seneca history and culture, a fragment of Parker's diary, 1847, and a significant quantity of material on the Seneca language assembled by Asher Wright.

The Thomas Jefferson papers contain a large number of correspondence both to and from Jefferson, as well as various other material related to American Revolutionary War and Early Republic. Includes correspondence with Patrick Henry, Charles Willson Peale, Richard Henry Lee, Horatio Gates, David Rittenhouse, Robert Patterson

James Burd (1726-1793) was well-known in colonial Pennsylvania through his role in the French and Indian War, as well as his connections to many of the colony's leading families (most notably the Shippen family). Initially starting out as a merchant in Philadelphia, Burd became increasingly involved with colonial affairs after moving to Lancaster County with his family in 1752. It would be on the frontier where Burd would make his mark first as a soldier, and later as a magistrate. The Burd-Shippen Papers consist mainly of letters and business documents sent to James Burd, with the bulk of the collection relating to the French and Indian War, 1754-1763, in which Burd served as an officer commanding troops at Fort Augusta and elsewhere. The collection reflects all aspects of Burd's life in Pennsylvania as a merchant, soldier, and magistrate; as well as his involvement with the Shippen family professionally and personally. Intermixed with items sent to Burd are receipts to his wife Sarah Shippen Burd, and correspondence between Edward Shippen and James Hamilton regarding land matters and Indian affairs in Lancaster.

The papers include miscellaneous letters, letterbooks, books, certificates, and diplomas of various members of the Muhlenberg family. Among them are photostats of letters and papers of General John Peter Gabriel Muhlenberg and officers of the Continental Army on military affairs in the Southern Department during the American Revolution (1772-1804); photostats of letters to Albert Gallatin, Nathanael Greene, Edward Hand, Winthrop Sargent, Baron von Steuben, William Alexander, and George Washington; photostat of General Muhlenberg's journal of trips to the Ohio (1784, 1797); photostats of letters and notes of Gotthilf H. E. Muhlenberg, including a diary kept at Halle (1771) and extracts of thirty letters to Stephen Elliott of Beaufort and Charleston, South Carolina (1808-1815); photostats of letters of Henry A. Muhlenberg about his biography of General Muhlenberg (1848-1849); and photostats of letters of Henry Melchior Muhlenberg (1711-1787). Also included is an original letterbook of Peter Muhlenberg, paymaster of the United States Army, kept at Augusta and Savannah, Georgia (1836-1842). Henry Muhlenberg's notebooks (1784-1813), written in Latin or German script, in a small hand, includes a wealth of botanical observations, with a focus on Lancaster, Pennsylvania. The Henry Muhlenberg journals are a record of daily occurrences, with many features of a commonplace book, containing prescriptions, notes of questions asked candidates for the Lutheran ministry, and the plan of a barn. There is also a biographical account of Rev. Henry Melchior Muhlenberg (1711-1787).

A physician, natural historian, and professor at the University of Pennsylvania, Benjamin Smith Barton (1766-1815) was one of the central figures in Philadelphia's early national scientific establishment. Having received his medical training in European universities, Barton was appointed Professor at the University of Pennsylvania in 1789, lecturing on botany, materia medica, natural history. A prolific author, he established his reputation as one of the nation's preeminent botanists through his botanical text book The Elements of Botany (1803), but his contribtions to zoology, ethnology, and medicine were equally noteworthy. Barton's monograph on the "fascinating faculty" of the rattlesnake and his efforts in historical linguistics (New Views of the Origin of the Tribes and Nations of America, 1798) were widely read, and his Philadelphia Medical and Physical Journal (1804-1809) was one of the nation's first medical journals and an important outlet for natural historical research. The Barton Papers offer a comprehensive view of the professional work of Benjamin Smith Barton from the time of his return to the United States in 1789 until his death. The collection is divided into five series: Correspondence, Subject Files, Bound Volumes, Graphic Materials, and Printing Plates. The collection includes a particularly valuable series of botanical, medical, and natural historical drawings collected by Barton for research, reference, and publication. Among the many artists represented are William Bartram, Frederick Pursh, Pierre Turpin, and Benjamin Henry Latrobe.

A product of the distinctive culture of reform in antebellum Philadelphia, William Parker Foulke was the scion of the old elite who put a conservative stamp on social change. Trained as an attorney, Foulke spent much of his adult life engaging his deep amateur interest in natural history and mental philosophy and devoting himself to a variety of civic and philanthropic causes, including the colonization of formerly enslaved persons, penal reform, and cultural institutions in his native Philadelphia. The Foulke Papers are the product of the diverse social and intellectual interests of the Philadelphia attorney and philanthropist William Parker Foulke. Consisting primarily of correspondence, notes, and essays, the collection touches on Foulke's many interests. The collection includes numerous lectures delivered by Foulke along with material on the Lancaster County Prison, New York Prison Association, and the Philadelphia Society For Alleviating the Miseries of Public Prisons; notebooks concerning prisons and prisoners, including a 1846-1852 diary, and a listing of prisoners, their race, age, crime, sentence, and observations; a diary concerning the American Colonization Society (1852); a copy of an arctic diary (1853-1854) by John Wall Wilson, in the hand of Isaac Israel Hayes, which recounts much of the journey aboard the brig Advance, commanded by Elisha Kent Kane. There is also a list of buildings (1820-1841) designed by John Haviland, and material on the American Academy of Music, Philadelphia.