François, comte de Barbé Marbois (1745–1837), diplomat, was born in Metz, France, where he was educated before studying law in Paris. In 1768 he obtained his first position in the foreign office, and thereafter he enjoyed a long career in France and abroad as a diplomat and politician, including service in the United States as secretary to the French legation beginning in 1779 and as chargé d’affaires, 1784–85. During his time in America, Barbé Marbois circulated a questionnaire on behalf of the French government that sought information about the individual American states. TJ’s 1780–81 response was eventually published as Notes on the State of Virginia. They corresponded only rarely, but in 1783 Barbé Marbois helped TJ find a French tutor in Philadelphia for his daughter Martha Jefferson (Randolph). As minister of the public treasury, Barbé Marbois negotiated the Louisiana Purchase Treaty in 1803. He was elected to the American Philosophical Society in 1780, serving as councillor, 1781–85, and he became a member of the Institut de France in 1816. Barbé Marbois authored works on subjects that included agriculture, geography, and history. He died in Paris (DBF description begins Dictionnaire de biographie française, 1933– , 19 vols. description ends ; Hoefer, Nouv. biog. générale description begins J. C. F. Hoefer, Nouvelle biographie générale depuis les temps les plus reculés jusqu’a nos jours, 1852–83, 46 vols. description ends , 4:428–31; E. Wilson Lyon, The Man Who Sold Louisiana: The Career of Francois Barbe-Marbois [1942; repr. 1974]; PTJ description begins Julian P. Boyd, Charles T. Cullen, John Catanzariti, Barbara B. Oberg, and others, eds., The Papers of Thomas Jefferson, 1950– , 40 vols. description ends , esp. 4:166–7, 6:373–4, 34:xli–xlii, 423–4n; Notes, ed. Peden description begins Thomas Jefferson, Notes on the State of Virginia, ed. William Peden, 1955 description ends , xii–xv; Philadelphia Pennsylvania Packet or the General Advertiser, 27 Jan. 1780; APS description begins American Philosophical Society description ends , Minutes, 5 Jan. 1781, 2 Jan. 1784 [MS in PPAmP]; Miller, Treaties description begins Hunter Miller, ed., Treaties and other International Acts of the United States of America, 1931–48, 8 vols. description ends , 2:498–528).

The interesting narrative of Benedict Arnold’s plot was Barbé Marbois, Complot d’Arnold et de Sir Henry Clinton contre les États-Unis d’Amérique et contre le Général Washington. Septembre 1780 (Paris, 1816; Poor, Jefferson’s Library description begins Nathaniel P. Poor, Catalogue. President Jefferson’s Library, 1829 description ends , 4 [no. 138]). TJ’s copy in MoSW includes a handwritten, signed inscription by Barbé Marbois dated Paris, 30 Dec. 1816: “L’auteur aime à croire que Monsieur Jepherson a gardé de lui quelque Souvenir, Il lui offre cet opuscule et l’hommage de Son respect” (“The author, liking to believe that Mr. Jefferson has retained some memory of him, offers him this opuscule and the tribute of his respect”). Barbé Marbois also sent a copy of this work to James Madison some time before October 1817 (Madison, Papers, Retirement Ser., 1:139–40).

The personal sufferings Barbé Marbois experienced during the French Revolution included exile to French Guiana by the Directory in 1797 (Lyon, Man Who Sold Louisiana, 95–112). Montesquieu stated his principle that large republics could not survive in book eight, chapter sixteen of his Esprit des Lois (De l’Esprit des Loix [Geneva, 1748], 1:195–7).