Born at St-Martin de Ré, France, on June, 1760, DuPonceau received his education at a Benedictine college, where he demonstrated a facility for languages. His uncommon knowledge of English led to ridicule by his schoolmates, who nicknamed him L'Anglois for his habit of carrying around an English Classic in his pocket. A bit of jealousy may have been at play as DuPonceau, though he rarely studied, received all of the premiums at the end of each year. The disdain was mutual: DuPonceau scorned his fellow students for their tendency to merely memorize and repeat their lessons.

Dissatisfied with the scholastic philosophy taught at the college, DuPonceau left the school after eighteen months. DuPonceau's mother wanted him to enter the priesthood. In an effort to persuade him, the priest reportedly evoked feelings of guilt and remorse by reminding DuPonceau of his failure to cry at his father's death. Under the combined pressure of his mother and the unnamed priest, DuPonceau agreed to enter the seminary under the condition that they would not require him to enter the priesthood after he completed his studies. He completed his studies, but did not enter the priesthood. Instead, at the age of 17, he set out for America with Baron von Steuben and served as Steuben's secretary in the Revolutionary army, with rank of captain, until illness forced his resignation in 1781. He settled in Philadelphia, where he studied law, was admitted to the bar, and established a law practice.

Elected to the American Philosophical Society in 1791, he served as secretary for and primary force behind the Society's Historical and Literary Committee. One of the most active committees in the Society's history, the Historical and Literary Committee provided much of the impetus for the early growth of the Society's Native American Indian linguistic collections. During DuPonceau's tenure as secretary, the Committee laid the foundation for the Society's development into one of the premier centers for the study of Native American Indian languages.

A member of the Society during the era in which Thomas Jefferson served as president of the American Philosophical Society as well as president of the United States, DuPonceau collaborated with Albert Gallatin on a volume of Indian vocabularies commissioned by Thomas Jefferson. Jefferson wished to demonstrate the relationships between Indian tribes based on the similarities or differences of their languages. DuPonceau and Gallatin found that a correlation did exist between similarity of language and the length of time since the tribes had migrated to other regions.

His memoir on the grammatical system of the Indian languages (Mémoire sur le systeme grammatical des langues de quelques nations Indiennes de l'Amérique du Nord) won the Volney prize of the French Institute in 1835 and his writings continue to inspire scholars to this day. In addition to his works on Indian languages, DuPonceau wrote on the Chinese system of writing, then largely a puzzle to most Europeans.

An active and influential scholar, DuPonceau served, simultaneously at one point, as president of not only the American Philosophical Society, but also of the Athenaeum and the Historical Society of Pennsylvania. During his years as president of the Society, from 1827 until his death in 1844, the Society expanded its linguistics collection to a degree not seen again until the 20th century.

The collection includes DuPonceau's correspondence to and from various persons, essays, and legal papers. Though it consists largely of routine correspondence regarding legal matters and reviews of publications, the collection includes several essays of interest to scholars of maritime law and a few items of general historical interest.

Items of particular historical interest include two letters from John Adams and two letters from his son John Quincy Adams, written during their respective terms as President of the United States, George Washington's statement regarding DuPonceau's military service, and a legal document pertaining to the DuPont family of Delaware. The Adams letters include one in which Adams states that DuPonceau's work on Native American Indian linguistics has changed his perceptions of the Indians. The Washington document, which includes Washington's signature, describes DuPonceau's appointment as a captain and his service as aide de camp and secretary to Major General Baron Steuben during the campaigns of 1778 through 1780. The DuPont document includes the signatures of five members of the prominent manufacturing family.

Other noteworthy items include letters from the Marquis de Lafayette, Albert Gallatin, and Charles Meredith. The Lafayette letter is an 1835 introduction of Dr. Charles Kraitsir, a philologist who published, the following year, what is perhaps the first history of the Polish in America. The Meredith letter discusses Robert Livingston's motion favoring the empowerment of the congressional Judiciary Committee to handle deeds and affidavits pertaining to land. The two Gallatin letters includes one that informs DuPonceau of his progress on the Indian vocabularies and another that includes a newspaper clipping defending Gallatin against those who assailed his reputation.

The collection also includes several letters written in French. Most relate to legal matters or reviews of publications, but some include a few interesting historical tidbits, among them discussion of the representation of French sailors in North Carolina, the Polish victory over the Russians, Andrew Jackson's dismissal of agnostics (including DuPonceau), and John D. Hunter, allegedly raised among the savages, but proven an impostor. The last item contains a relevant newspaper clipping from Poulson's Daily Advertiser.

One of the few personal items in the collections is a reflective letter from DuPonceau to William Popham, written two years before his death. Although he describes his "general health" as good, DuPonceau felt that he was "gradually departing from this world." He describes his declining eyesight and hearing, comments upon the death of the last friend of his youth, John Vaughan, and remarks that few living persons remembered him as a young man.

None.

The Peter Stephen DuPonceau Collection consists of 14 letters acquired by the APS in 1961 and 107 letters and essays removed from the APS Miscellaneous Manuscripts Collection.

Cite as: Peter Stephen DuPonceau Collection, American Philosophical Society.

Recatalogued by Valerie A. Lutz, September 2004.

As one of the most active members of the American Philosophical Society during his lifetime, DuPonceau appears, not surprisingly, in several other collections:

• American Philosophical Society Archives, which includes many letters to and from DuPonceau
• Peter Stephen DuPonceau Commonplace Book (B H978), with notes on William Penn and the Penn family (B D92c)
• Peter Stephen DuPonceau, Essai de solution du problème philologique proposé en l'année 1823 par la commission de l'Institut de France (410 D92.1)
• Peter Stephen DuPonceau, Indian vocabularies, consisting of 82 vocabularies representing 73 languages with notes and additions made by Du Ponceau and Albert Gallatin. (497 In2)
• Peter Stephen DuPonceau, Notebooks on Philology, consisting of nine volumes, principally on American Indian languages, with some notes on the languages of the Tartars, Arabs, Greeks, Polynesians, and others. (410 D92)
• Peter Stephen DuPonceau, Sea terms in different languages (359.03 D92)
• John Heckewelder Papers, with 115 letters written to DuPonceau, chiefly on Indian languages (497.3 H35o)

DuPonceau collections at other repositories include:

• DuPonceau, Peter Stephen, 1743-1824. Manuscript of DuPonceau's diary, kept during his first months in America (1777-1778), which includes plans of the Valley Forge encampment.

• Chambers, Gordon. Collection, 1792-1823 (44 items). Includes material relating to Peter Stephen DuPonceau.
• Du Ponceau, Peter Stephen, 1760-1844 Stephen, 1760-1844, 1760-1844, 1760-1844. (1760-1844). Correspondence, 1777-1844 (2 volumes)
• One volume consists mainly of copies of incoming letters, 1777-1785, 1808-1839, on political and legal matters from John Adams, John Quincy Adams, Washington Irving, Marquis de Lafayette, Edward Livingston, James Madison, James Monroe, and others, with some copies of outgoing correspondence.
• The other volume is DuPonceau's reminiscences of his life to 1783 in the form of letters, 1836-1844 to Robert Walsh and later to his granddaughter, Anne L. Garesche. The memoirs concern his formal and informal education in France and his service as an aid to Baron von Steuben and General Nathanael Greene during the American Revolution.
• Both volumes contain a table of contents. There are also a few miscellaneous letters and notes.
• Steuben, Friedrich Wilhelm Ludolf Gerhard Augustin, Baron von (1730-1794). Letters, 1777-1791, 1835, 1837. (15 items.) Letters of Friedrich Wilhelm von Steuben relating to his military service in the Revolutionary Army; includes two letters of Peter Stephen DuPonceau, 1835, 1837.
• Hopkinson family. Papers, 1735-1863 (19 v.) Includes correspondence with Peter Stephen DuPonceau.

• Speculation Land Company Records (1796-1909). These pertain to lands in New York State owned by DuPonceau and Abraham Kintzing of Philadelphia.
• Eccles Family Papers. These include the papers of Edward Jones (1762-1841) of Wilmington
• and Fayetteville, N.C., native of Ireland, merchant, lawyer, and solicitor-general of North Carolina; and of his son-in-law, John Dick Eccles (d. 1856), also of Fayetteville. The collection includes letters from DuPonceau, a friend of Jones.

• University Archives, Trustee Records. Two documents from the period of DuPonceau's trusteeship.