Peter Stephen DuPonceau

Pierre-Étienne (Peter Stephen) Du Ponceau
Du Ponceau, circa 1830
Born	June 3, 1760 Saint-Martin-de-Ré, France
Died	April 1, 1844 (aged 83) Philadelphia, United States
Occupation	Philosopher, linguist, jurist

Peter Stephen Du Ponceau (June 3, 1760, Saint-Martin-de-Ré, France – April 1, 1844, Philadelphia, United States) (also Pierre-Étienne du Ponceau) was a French linguist, philosopher, and jurist. After emigrating to the colonies in 1777, he served in the American Revolutionary War. Afterward, he settled in Philadelphia, where he lived the remainder of his years. He contributed significantly to work on the indigenous languages of the Americas, as well as advancing the understanding of written Chinese.

Du Ponceau studied at a Benedictine college, where he gained an interest in linguistics. However, he abruptly ended his education after only 18 months over a dissatisfaction with the scholarly philosophy taught at the college. He emigrated to America in 1777, at age 17, with his reputed lover Baron von Steuben, who was 30 years his senior.

Du Ponceau served as a secretary to Steuben in the Continental Army during the American Revolution. After the war, he settled in Philadelphia, where he would spend the rest of his life. He was a good friend of Lafayette.

Du Ponceau joined the American Philosophical Society in 1791 and later served as its president, from 1827 until his death. He became notable in the field of linguistics for his analysis of Indigenous languages of the Americas; as a member of Society's Historical and Literary Committee, he helped build a collection of texts that described and recorded the native languages of the Americas. His book concerning their grammatical systems (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. In 1816 he was elected a member of the American Antiquarian Society, and he was elected a Fellow of the American Academy of Arts and Sciences in 1820.