I'm afraid I don't get the question. What do the keys to a cabin have to do with the library gift? Or is that the title? ("Keys to a cabin"?) Or "Uncle Tom's Cabin"?
PS: Is figuring the President not part of the question? If not so (not not part of...) I guess Roosevelt or earlier because cabin reminds of hunting, and I think later Presidents would have had a(nother) villa instead of a cabin.