Memoir by Mark Twain detailing his days as a steamboat pilot on the Mississippi River before the American Civil War. Beginning with a brief history of the river from its discovery in 1541, it continues with anecdotes of Twain's training as a steamboat pilot. He describes, with great affection, the science of navigating the ever-changing Mississippi River. The second half of the book Twain describes his return, many years later, to travel on a steamboat from St. Louis to New Orleans. He observes the competition from railroads, the new, large cities, and discusses his notions of greed, gullibility, tragedy, and bad architecture.