This volume contains approximately 175 letters written by Thomas Penn and Richard Penn on public business. A few are copies of letters by James Hamilton, a member of the Provincial Council and lieutenant governor of Pennsylvania, and by or to Abraham Taylor.

David Rittenhouse (1732-1796) was one of the most prominent American men of science of the 18th Century. A skilled instrument maker, Rittenhouse was the an astronomer, playing a major role in recording the 1769 Transit of Venus, among many accomplishments. Rittenhouse also conducted important survey work for the state of Pennsylvania, establishing the state's western border, as well as overseeing the completion of the Mason-Dixon survey. In addition to his scientific endeavors, Rittenhouse's work for American independence places him among the important founding fathers. Subordinating his scientific interests for the greater good of Pennsylvania during the American Revolution, Rittenhouse served as a member of both the Pennsylvania Assembly and the Pennsylvania Constitutional Convention, and held powerful positions on the Pennsylvania Council of Safety and the subsequent Committee on Safety. Rittenhouse also served as the first director of the United States' Mint, at the behest of President George Washington. Rittenhouse was elected to the American Philosophical Society in 1768 and played a major role in placing the Society on the scientific map. He held many positions in the Society, including serving as its President from 1791 until his death in 1796. The Rittenhouse papers span 1774 to 1932, and consist of 61 items, over 0.25 linear feet. The collection is comprised mainly of correspondence, but also includes receipts, genealogies and broadsides.

Correspondence from Charles Mason and Jeremiah Dixon to Thomas Birch, and Nevil Maskelyne to Charles Mason, relating to the survey, and the transits of Venus (1761,1769).

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.

A leading national opinion maker and influential regional politician, tied by marriage to the families of Benjamin Franklin and cognate families, William Duane (1760-1835) played key roles in the field of political journalism, as well as national, Pennsylvania and local Philadelphia politics. Editor of the Aurora, William Duane (1760-1835) assured himself gratitude from Jefferson and the Republicans and enmity from President Adams and the Federalists for his open and effective attacks on Federalist policies. His son William John Duane (1780-1865), was a prominent member of the Pennsylvania legislature, a legal advisor to Stephen Girard, Solicitor for many of Philadelphia's premier institutions, and Secretary of the Treasury of the United States (June-September 1833). The Duane Family Collection contains a diverse assemblage of personal and professional correspondence relating to family members, with interesting material relating to William Duane (1760-1835), his son, William John Duane (1780-1865), grandson William Duane (1808-1882), great-grandson Charles Williams Duane (1837-1915), and other relations. The collection includes unique correspondence from and relating to Benjamin Franklin's family, as well as correspondence with Thomas Jefferson and other leading figures from the early nineteenth century. The collection also includes prints, photographs of family members, as well as some maps.

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.

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 Calendar of the Papers of Benjamin Franklin prepared by Isaac Minis Hays for the bicentennial of Franklin's birth in 1906 provides access to the largest portion of the Franklin Papers at the APS. The items were originally bound into volumes in roughly chronological order, with letters to Franklin preceding those from Franklin and at the end of the collection, Franklin's letters owned by the University of Pennsylvania. Each manuscript is still identified by Hays' reference numbers, which include a roman numeral refering to the original volume followed by an arabic number to identify the folio. The electronic version of the finding aid replicates Hays' calendar, including the introductory material and item-level descriptions. It has been updated to reflect corrections in the metadata, corrections of personal names, dates, and description.

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