In the middle of the eighteenth century, Honoré Blanc was inspired by the work of French artillerists led by Jean-Baptiste Vaquette de Gribeauval, who had begun pursuing interchangeability in artillery.
When Blanc tried to interest fellow European craftsmen in the concept, they were unreceptive, due to a combination of skepticism as to the system viability and some amount of fear that their employment and/or status might be threatened by it if it did work.
Jefferson tried to persuade Blanc to move to America, but was not successful, so he wrote to the American Secretary of War with the idea, and when he returned to the USA he worked to fund its development.
[4] Blanc, and the interchangeable musket parts experiment, is highlighted in a multi-page footnote in Mémoire sur la fabrication des armes portatives de guerre by Gaspard Hermann Cotty (1806).
Roe (1916) mentions an unknown French inventor in whose work Thomas Jefferson took an interest circa 1785 and remembered years later as a "Mr Le Blanc".