Again, I know we've been over this ground before (some years ago), but I have to say that the introductions for sections of the Mark Twain Project letters volumes give excellent biographical treatments of the relevant periods. Add the introductory materials in the MTP works and you've got very close to a full biography. Of course, this collection of biographical essays lacks the narrative coherence that many readers want in a Biography, but the only way to give narrative a coherence is to be very selective. Such selection makes for fine reading, but not necessarily for fine understanding. Which returns us to the question, what does one seek in a biography? Gregg Camfield