Barbeu du Bourg met Lord Bolingbroke in Paris when he was serving as tutor in the house of Matignon during the late 1730s or early 1740s (he arrived in Paris around 1738). In 1752 he published a 2 volume French edition of Bolingbroke's Letters on the Study and Use of History. In the preface to his translation Barbeu du Bourg explains that in 1741 Bolingbroke had given him a rare copy of the letters printed by Alexander Pope in 1738 but intended for circulation among Bolingbroke's friends only. According to Barbeu du Bourg, Bolingbroke authorized him to make a translation from this edition, as long as he promised not to publish it until after his death. Barbeu du Bourg claims that he worked from the Pope edition but compared it to the edition prepared by David Mallet and published by Millar in 1752. The BNF catalog also includes a supposed work of Bolingbroke's translated by Barbeu du Bourg as Le Siècle politique de Louis XIV ("A Sièclopole: aux dépens de la Compagnie, 1753), with an additional edition printed in Dresden in 1755. Worldcat lists the full title as "Le Siècle politique de Louis XIV, ou Lettres du Vicomte Bolingbroke sur ce sujet: avec les Pièces qui forment l'histoire du siècle du M. F. de Voltaire, et de ses querelles avec Mrs de Maupertuis et la Beaumelle, suivies de la disgrâce de ce fameux Poète".

Barbeu du Bourg met Benjamin Franklin in 1767 and the two men began to correspond. But Barbeu du Bourg was already familiar with Franklin's scientific work and had published some of Franklin's writings in his Gazette d'Épidaure as early as 1762. These were excerpts from Franklin's correspondence with Dalibard, who had done the first French translation of Franklin's work, the Expériences et observations sur l'électricité, in 1752 ("Moyen éprouvé pour préserver de la foudre les maisons et ceux qui les habitent", "Sur le préservatif du Tonnerre" (Dalibard's account of the lightning rod), "Extrait d'une Lettre de M. Franklin, de Londres, le 9 décembre 1761, à M. Dalibard à Paris," Extrait d'une Lettre M. Kinnserley de Philadelphie le 12 Mars 1761, à M. Franklin à Londres" and "Extrait d'une Lettre de M. Franklin à M. Dalibard. De Londres 20 Mars 1762". In 1768 Barbeu du Bourg supervised the translation of Franklin's 1766 testimony before the House of Commons regarding the American response to the Stamp Act. This appeared in the Ephémérides du citoyen (vol. 8, p. 34-91 and vol. 9), a periodical that ran from 1765 to 1772 and published writings by the physiocrats. Barbeu du Bourg promoted Franklin's own scientific discoveries as well as the American cause more generally. In this context he wrote a work called Lettre d'un Philadelphien à un ami de Paris, translated Dickinson's Letters of an American Farmer (1769) and produced the Calendrier de Philadelphia (1778). He published another work called Le Petit Code de la riason humaine in 1774, and Franklin eventually had this translated into English and printed in London. In 1773 he produced a French edition of Benjamin Franklin's scientific works (which included some parts translated by Jean-Baptiste Lesqui or Lécuy) to which Barbeu du Bourg added some letters that Franklin had addressed to him. He translated additional shorter works by Franklin, such as a letter by Franklin on the use of oil to calm sea waves, which had been read by the Royal Society and appeared translated in the Journal des Savants.

In addition to Franklin, Barbeu du Bourg also corresponded with (and met) the Philadelphia physician Benjamin Rush, to whom he expressed an interest in translating the Transactions of the American Philosophical Society as well as a description of Philadelphia by D. Smith, but apparently neither of these projects took off. He also had an idea for a publication (perhaps in periodical form) called Le Correspondant de Philadelphie which would print correspondence on contemporary political, social and economic topics in an effort to foster exchanges between reform-minded writers in France and America. He probably contributed additional writings and translations to Ephémérides du Citoyen and may have also contributed to the Affaires de l'Angleterre et de l'Amérique, though in both cases attribution is difficult. He was an important contact for Franklin when he first arrived in France in 1776 and was seen by contemporaries (such as the British ambassador) as someone who spread reports and rumors in favor of the Americans.