Selling by subscription was a popular method which Twain used, believing that pre-orders were an indication of success. "The big sale," Twain wrote to publisher James R. Osgood a month before the book's release, "is always before issue... The orders that come in after the issue of a subscription book don't amount to a damn." He called his own prediction a "moral maxim," one which was "truer than nearly anything in the Bible." Osgood was less experienced with subscription sales and balked at Twain's suggestion that 100,000 should sell before its release. Twain was half-right: subscriptions were high, but it was later sales that made the book a best-seller by year's end.
Osgood and Twain had differing ideas about the book. Osgood hoped for a conventional travel narrative which would be easily accepted by the public. Twain, however, created something which remains unconventional and somewhat formless. The book opens:
The Mississippi is well worth reading about. It is not a commonplace river, but on the contrary is in all ways remarkable. Considering the Missouri its main branch, it is the longest river in the world—four thousand three hundred miles. It seems safe to say that it is also the crookedest river in the world, since in one part of its journey it uses up one thousand three hundred miles to cover the same ground that the crow would fly over in six hundred and seventy-five. It discharges three times as much water as the St. Lawrence, twenty-five times as much as the Rhine, and three hundred and thirty-eight times as much as the Thames. No other river has so vast a drainage-basin; it draws its water supply from twenty-eight States and Territories; from Delaware, on the Atlantic seaboard, and from all the country between that and Idaho on the Pacific slope—a spread of forty-five degrees of longitude. The Mississippi receives and carries to the Gulf water from fifty-four subordinate rivers that are navigable by steamboats, and from some hundreds that are navigable by flats and keels. The area of its drainage-basin is as great as the combined areas of England, Wales, Scotland, Ireland, France, Spain, Portugal, Germany, Austria, Italy, and Turkey; and almost all this wide region is fertile; the Mississippi valley, proper, is exceptionally so.
*Significantly more information on this book can be found in Horst Hermann Kruse's Mark Twain and "Life on the Mississippi" (1982). Biographer Ron Powers gives the date of issue as May 17.