D0429700 (do͞o pŏnt′ də nə-mo͝or′, dü pôN′), Pierre Samuel 1739-1817. French-born economist and politician who took part in negotiations after the American Revolution (1783) and in the acquisition of the Louisiana Territory (1803). His son Éleuthère Irénée (1771-1834) established a gunpowder works in Delaware (1802) that developed into the chemical firm of E.I. du Pont de Nemours and Company.