For the readers of the late nineteenth century Samuel Clemens was first and foremost a travel writer, not a novelist. He earned his greatest respect and patronage from his contemporaries not for being the author of The Adventures of Huckleberry Finn (1884), as most modern readers assume, but for being the endearing narrator of his popular travel books. Excluding collections of short stories and sketches and a short burlesque autobiography, four of Clemens's first seven books published in the United States are travelogues: The Innocents Abroad, or the New Pilgrims' Progress (1869), Roughing It (1872), A Tramp Abroad (1880), and Life on the Mississippi (1883). He published his fifth and last travel book, Following the Equator, in 1897. These lengthy volumes, along with his many periodical travel pieces that were often incorporated into the books, were instrumental in forming his popular and literary identity. America's most beloved author was, first, its most effective and...