Lyndon B. Johnson, Vice-President during the Kennedy era stepped into the President's shoes in late 1964 following the death of Kennedy. His foreign policies with regard to Europe were basically a continuation of those put in place by Kennedy. George Ball remained in his position as under-Secretary and once again provided the necessary link for Monnet to influence the American administration. David Bruce in an oral history interview stated that Johnson was greatly impressed by Monnet and his admiration was reciprocated. We can see from Monnet's correspondence with Johnson that he respected the President's opinion not only for his advocating policies such as non-proliferation of nuclear weapons but also for his domestic social and economic reforms.

The originals are held in various Archives and Presidential Libraries in the USA