Roger Boylan at the Boston Review writes about the flourishing posthumous career of Mark Twain: “…more than 5,000 previously unknown letters of Twain’s have surfaced in the last 50 years. This represents an average of two new letters per week, but still only about one-tenth of the 50,000 or so he is believed to have written.” And at Slate, Craig Fehrman discusses the “brilliant brand management” behind the handling of Twain’s autobiography.