Patriarch of the fabled family of American politicians (1888–1969) who served as American ambassador to Great Britain from 1938 to 1940. TLS, one page, 7.25 x 10.5, personal letterhead, September 5, 1945. In response to an invitation to listen to his son, Jack, speak, Kennedy writes, in full: “Thank you very much for your kind invitation to listen to my son speak on September eleventh. On that day, however, I will be speaking in the western part of the state on the establishment of a Department of Commerce in Massachusetts. I have seen some of the material which Jack is getting together and I am sure it will be very interesting. We both feel quite honored that Jack has this splendid opportunity. I only regret that I can’t be with you.” In very good condition, with scattered moderate creasing, uniform toning, a few light spots of soiling and foxing, damp staining to the lower right, and a faint rusty paperclip imprint at the top edge, none of which affect the bold, crisp signature. RRAuction COA.