As a mature man, Mark Twain would always look to the past as a happier and more innocent time than the present.

He cherished and often wrote about his boyhood in Hannibal and his brief career as a Mississippi riverboat pilot.

In his writings he gave these earlier periods of his life an almost mythical coloring.

Over the years, Twain would also wrap himself in the trappings of mythology.

As Wood makes clear, Twain was never deeply concerned with the literal truth about his own life, especially if his imagination could improve upon its events. Humor was also part of these exaggerations—a humor that Twain learned on the fringe of the frontier in his Missouri days, and later on the frontier itself in the far West. Wood details Twain's development as an unsurpassed humorist, revealing that the passionate Twain was capable of...