The first American novel to be published in the vernacular, it is an exemplar of local color and regionalism. Narrated by Huck, it begins where Tom Sawyer left off, and follows Huck as he fakes his own death in order to escape his physically abusive, drunken father, as he and the escaped slave Jim (at times known as N----- Jim) travel down the Mississippi, escaping the fictional town of St. Petersburg, Missouri. Over the course of the novel, Huck adopts many different personas at the spur of the moment, at one point even trying to pass as a girl. This scene in particular is a good example of the kind of social insight the novel excels at, as Huck’s real gender is found out through a series of “tests”—threading a needle, throwing, and catching. Huck’s conditioned reflexes give him away. Huck and Jim travel part of the way with two conmen who refer to themselves as the Duke and the King; though Huck is willing to go along with their shams to a certain extent, his realization of their effect on other people coupled with the realization that they have no sense of loyalty to him or Jim makes Huck eager to get loose of them. Finally, in the end section of the book, Tom Sawyer reappears, and joins Huck’s campaign to free the captured Jim. Tom makes the escape needlessly difficult, informed by his own adventure-story-fed-overactive-imagination. Huck’s surprise at Tom’s eagerness to help a slave escape is finally explained by Tom’s delayed explanation that the Widow Douglas has died, leaving directions in her will that Jim should be freed. Huck and Tom, then, go to great lengths to try to free a technically free slave.
It satirizes antebellum society, from the feuding Grangerfords and Shepherdsons to the more subtle subplot of Huck’s overcoming his own racism. While there have been debates about Twain’s use of the word n------ in the novel, his use of the words is not only historically accurate, but also helps illuminate the transformation in Huck’s thinking. After realizing the extent of Jim’s loyalty and recognizing Jim’s humanity, Huck rejects the advice of his "conscience", which continues to tell him that in helping Jim escape to freedom, he is stealing Miss Watson's property. Accepting that "All right, then, I'll go to hell!", Huck resolves to free Jim. By the end of the novel, Tom’s Aunt Polly appears to set everyone straight about Tom’s and Huck’s real identities (they had fooled his Aunt Sally and Uncle Silas that they were Sid and Tom Sawyer), and sets everyone to rights. Jim’s freedom is announced, and he is commended for his care of Tom and Huck.