Book excerpt: Introduction. Mark Twain's own letters from the Earth -- Part I. The Mississippi. The lure of the river -- More river thoughts -- Steam boat magic and a small town boy -- The face of the water -- Goin' to the theater in the big city (a letter from "Thomas Jefferson Snodgrass," 1856) -- Mardi-Gras in New Orleans (A letter to Pamela A. Moffett, 1859) -- A tour of New Orleans -- The scene of battle: Vicksburg -- Part II. The West. "Roughing it" lecture -- Among the miners -- The killing of Julius Caesar "localized" -- A trip to Tahoe -- Off for San Francisco -- A San Francisco day trip -- San Francisco weather and other natural events -- Part III. Back East. Philadelphia: the first visit -- New York: the overgrown metropolis -- New York: the dreadful Russian bath -- New York: changes in the city -- New York: street people -- New York: personal ads -- Plymouth Rock and the Pilgriims -- First visit to Boston -- Boston: a modern Cretan labyrinth -- Boston antiquities --