Released in 1883 by James R. Osgood & Co. First edition had 624 pages and 316 illustrations.			Twain incorporated passages from other books on the river when he discovered he didn't have enough material to fill out the book; he also included a portion from his unfinished Huckleberry Finn manuscript.
In the early 1870s, Twain wanted to write a account of his piloting days in an effort to perserve the memory of the rapidly disappearing steamboat era on the Mississippi.				The result was the Old Times on the Mississippi serial, published in seven installments in the Atlantic Monthly in 1875; the entire serial is included as chapters four to 17 of this book.
Twain enlisted publisher James Osgood and stenographer Roswell Phelps to accompany him on an return trip down the Mississippi to gather additional information for the book.			A chapter derogatory to Southerners was omitted at the last minute to avoid causing offense; the chapter was eventually released in 1913 as The Suppressed Chapter of Life in the Mississippi..

The case is very different in the South. There, every man you meet was in the war; and every lady you meet saw the war. The war is the great chief topic of conversation. The interest in it is vivid and constant; the interest in other topics is fleeting. Mention of the war will wake up a dull company and set their tounges going, when nearly any other topic will fail. In the South, the war is what A.D. is elsewhere: they date from it. All day long you hear things "placed" as having happened since the waw; or du'in the waw; or befo' the waw; or right aftah the waw; or 'bout two yeahs or five yeahs or ten yeahs befo' the waw or aftah the waw. It shows how intimately every individual was visited, in his own person, by that tremendous episode. It gives the inexperience stranger a better idea of what a vast and comprehensive calamity invasion is that he can ever get by reading books at the fireside.

Life on the Mississippi is both a memoir, a travel book, and a loose collection of history, geography, folklore, and other scraps of interesting tidbits.

After a short three-chapter intro about the geography and history of the Mississippi River, the first part of the book is a lengthy memoir of Sam Clemens' experiences as a cub steamboat pilot. He is tutored by Horace Bixby, who agrees to teach him the river between New Orleans and St. Louis for $500. Twain recalls the explosion of the steamboat Pennsylvania, which killed at least 150 people, including his brother Henry.

The remainder of the book describes Twain's return to the Mississippi after 21 years, with a poet and a stenographer (Osgood and Phelps). The travellers start in St. Louis and take a packet called Gold Dust downriver. Twain discovers the pilot, Robert Styles, was a cub pilot at the same time as Twain. As the boat travels down the Mississippi, numerous anecdotes are recalled and detailed descriptions of the landscape are given. Twain mentions that the Gold Dust explodes, killing 17 people, in August 1882, a few months after Twain's voyage.

Upon reaching New Orleans, G.W. Cable gives the travellers a tour of the city. Twain recalls a memory of his visit to the Mardi Gras. Twain also tells how he got his pen name from pilot Isaiah Sellers.

After leaving New Orleans, Twain arrives at his boyhood home of Hannibal, Missouri, for three days. Upon being asked what happened to Sam Clemens, a stranger in the town calls his "another d-d fool" who surprised everybody with his success. Twain surveys the town from Holliday's Hill, and recalls families in the town when he was a boy. Twain is struck with the changes that have taken place in Hannibal, now a small city of 15,000 people.

The travellers continue upstream to Iowa, Illinois, and Wisconsin. The trip ends in St. Paul, Minnesota, a distance of 2,000 miles from their starting point at New Orleans.