“I expect it to make about three hundred pages, and the last hundred will have to be written in St. Louis, because the materials for them can only be got there. . . . I may be an old man before I finish it,” he said then. Five years later, he told his wife, Olivia, he intended to go back to the river and spend two months taking notes: “I bet you I will make a standard work.” Nothing came of this plan either. Late in 1874, struggling to come up with an idea for an Atlantic Monthly article and complaining that “my head won’t ‘go’,” he suddenly (by his own account) discovered—or rediscovered—a perfect, untapped subject: “Old Mississippi days of steamboating glory and grandeur as I saw them (during 5 years) from the pilothouse.” “I am the only man alive that can scribble about the piloting of that day,” he told Howells. The subject was not only his alone but seemingly inexhaustible. “If I were to write fifty articles they would all be about pilots and piloting.” He settled down to work with the enthusiasm and optimism he tended to show at the beginning and middle of any new project.

Always a storyteller favoring atmospheric over literal truth, in order to enhance the drama and credibility of his narrative he changed some of its main circumstances. He was not, as he claims, an untraveled boy of seventeen, when Horace Bixby signed him on as his “cub.” Instead, he had been twenty-two years old and had already worked far from home as a printer in St. Louis, New York, Philadelphia, and Cincinnati. Until he realized that he needed both money and a ship to take him from New Orleans to Brazil, he had even contrived a visionary scheme to go up the Amazon and perhaps corner the market in coca, the shrub source of cocaine, an elixir reputed to have invigorating properties. And so far from being a shore-bound innocent—“I supposed all a pilot had to do was to keep his boat in the river”—he had rafted on the Mississippi and studied steamboats since childhood.

“ ‘Cub’ Wants to Be a Pilot”—the first of seven installments, written in rapid succession, of a series titled “Old Times on the Mississippi”—came out in the Atlantic Monthly in January 1875. It opens with the words “When I was a boy”—Mark Twain’s mantra for unlocking imagination and memory—and leads to one of the classic passages in American literature: “After all those years I can picture that old time to myself, the white town drowsing in the sunshine of a summer’s morning. . . . ” The cry of “S-t-e-a-m-boat a-comin!” also announces the arrival of Mark Twain, future author of Huckleberry Finn, and declares that his surge of power and spectacle, along with a prose manner that is both distinctively American and distinctively his own, derives not from polite or traditional literary sources but from “the great Mississippi, the majestic, the magnificent Mississippi, rolling its mile-wide tide along, shining in the sun.”

“The piece about the Mississippi is capital,” Howells wrote. “It almost made the water in our ice-pitcher muddy as I read it.” From the poet and journalist, and former private secretary to Abraham Lincoln, John Hay, born and raised in Warsaw, Illinois, fifty miles up the river from Hannibal, came another validation and tribute. “I don’t see how you do it. I knew all that, every word of it—passed as much time on the levee as you ever did, knew the same crowd and saw the same scenes—but I could not have remembered one word of it. You have the two greatest gifts of the writer, memory and imagination.”

Exhilarated by his rediscovered subject matter, Mark Twain believed at first he had enough material in hand to make a book to be published at the end of 1875. He was off by eight years and the several hundred additional pages that he needed to fill out his book and meet the length and bulk requirements of the subscription publishing trade. To pad it out he borrowed extensively, perhaps 11,000 words in all, from other writers, including the historian Francis Parkman. Chapter XXXVI (“The Professor’s Yarn”) is freestanding material heaved in from the author’s stock of unpublished or discarded manuscripts. Almost the whole of Chapter III is the raftsman’s chapter, 7,000 words or so, borrowed from Huckleberry Finn, “a book which I have been working at, by fits and starts, during the past five or six years, and may possibly finish in the course of five or six more.” Other material adapted from the novel includes the Darnell-Watson feud (Chapter XXVI) and the period-piece description of “The House Beautiful” (Chapter XXXVIII). Eventually he accumulated more filler material than he needed and moved chunks of it to appendices.

His six-week trip to the river gave him material and impetus for two books he was writing more or less simultaneously: Huckleberry Finn and Life on the Mississippi, both of them narratives that flow downriver into the deep South. The two books finished, he made preliminary notes for a third, this one never written: with Huck Finn cast as a cabin boy on a steamboat, it was to “put the great river and its bygone ways into history in the form of a story.”

“I never had such a fight over a book in my life before,” he told Howells as Life on the Mississippi was about to go to press: “I will not interest myself in anything connected with this wretched God-damned book.” His publisher insisted on some last-minute cuts (about 15,000 words in all) of material thought likely to offend loyal Southerners and sentimental Northerners. Olivia Clemens, always Mark Twain’s editor, was not only late in getting to the proofs but with 50,000 copies of Life on the Mississippi already printed, ordered two illustrations deleted—one showing a chopfallen corpse with staring eyes; another, the author being cremated, with an urn initialed “M.T.” standing in the foreground to receive the ashes.