Mark Twain House & Museum.

But beneath Clemens' projected gruff exterior rich with witticisms, DeBruyne says his most productive years were also his happiest years. Clemens, himself a former typesetter, saw the utility in a machine that could do so - but the investments (amounting to, today, millions of dollars) proved misguided, and when the machine failed to catch on, Clemens was in deep financial trouble. DeBruyne says Clemens' daughter Clara was instrumental in the process, returning to the home in the 1957 to create maps showing the original location of various key objects. [Extracted from the article]