Gribben has excellent notes on Twain's life-long interest in Franklin. I own
Twain's 1875 edition (3v) of Franklin's autobiography, with his annotations
in all three volumes.

I know of no works by Jefferson from Twain's library, but I have two books
that document information on Jefferson that Twain had readily available to
him in his own library (what did Twain know about Jefferson and when did he
know it...?)

Twain owned Thomas Wentworth Higginson's HISTORY OF THE U.S. (rev ed, 1905),
inscribing it in 1905 and making about 350 marks in the text, including
quite a few markings (marginal dots and underlined words) in the section (pp
329-46) that deals with Jefferson, including a page about the Sally "rumors"
(a passage that Twain marked in several places).

Twain also owned a book, Alexander K McClure's OUR PRESIDENTS AND HOW WE
MAKE THEM (2nd ed, 1902), inscribing it in 1902, but making no marks in the
text so far as I can tell. Three chapters deal with Jefferson, a summation
of the issues and elections returns for races in which Jefferson took part.

Kevin Mac Donnell
Austin TX 78730