When it was first published, responses to Adventures of Huckleberry Finn were fairly nonexistent until the Concord Public Library in Massachusetts announced that it was banning the book from its shelves. This action set off a public debate over the merits of the book. The most vocal were those who deemed the book to be unsuitable for children, fearing their corruption by exposure to its lower-class hero. Howard G. Baetzhold reports that beloved children's author Louisa May Alcott said about the book, "if Mr. Clemens cannot think of something better to tell our pure-minded lads and lasses, he had best stop writing books for them." Critics who demanded that literature be uplifting cited rough language, lack of moral values, and a disrespectful stance towards authority as the book's faults. But some critics rallied behind the author and wrote reviews that praised the book as a lasting contribution to American literature.

These early reactions are a fair indication of how the book has been received ever since. On the one hand, respected scholars have claimed the book as the core text of an American literary canon, where it has enjoyed a secure position since the 1950s. As Leo Marx claims, "Everyone agrees that Huckleberry Finn is a masterpiece." H. L. Mencken went so far as to dub the novel "perhaps the greatest novel ever written in English." Although some have questioned the formal coherence of the novel, arguing that the ending and Tom's burlesque escapades disrupt the text's quest for freedom, the general consensus has emerged that The Adventures of Huckleberry Finn is one of the most important works of American fiction ever written. But despite this resounding stamp of approval from the nation's leading literary scholars, secondary schools around the country have at various times questioned its suitability for students, even going so far as to ban the book. Whereas detractors of the novel from the previous century had been primarily concerned with its lack of decency and moral values, in the wake of the Civil Rights movement, the main concern of administrators, parents, and librarians has become that it promotes racism and demeans African American children with its extensive use of the word "nigger." Ultimately, the fear is that the complexity of the racial issues in the text may be too much for schoolchildren to comprehend. As Peaches Henry explains, "Parents fear that the more obvious aspects of Jim's depiction may overshadow the more subtle uses to which they are put."

Although in the past there have been sharp contrasts between the responses of scholarly and lay readers of The Adventures of Huckleberry Finn, the debate over the book's racial messages has more recently become the center of debate amongst literary scholars as well. The crux of the controversy is whether or not the novel presents an indictment of racism or simply reflects the generally accepted racist attitudes of the time period in which it was written. For most critics, the issue boils down to the depiction of Jim. For some, Jim is nothing more than a minstrel show stereotype, "the archetypal 'good nigger,' who lacks self-respect, dignity, and a sense of self separate from the one whites want him to have," in the words of Julius Lester. In these critics' eyes, Twain reveals his racism when he allows Tom to derail and hence belittle Jim's serious attempts to gain freedom and Huck's efforts to overturn society's view of blacks as property. But to others, a subtle satire on slavery and racism emerges from the text and takes precedence over any stereotypical depictions of African-Americans. Eric Lott argues, for example, "Twain took up the American dilemma (of race) not by avoiding popular racial presentations but by inhabiting them so forcefully that he produced an immanent criticism of them." According to Lott, the use of minstrel show stereotypes, exaggerated and ridiculous depictions of whites's false perceptions of blacks, has the effect of "making nonsense out of America's racial structures." Many critics agree with Lott, seeing the novel itself as a critique of the racism expressed by its narrator, Huck.

For many critics, however, Twain's conscious intentions about racial messages are not the issue. They see instead a variety of perhaps unconscious effects in the novel that point to new ways to understand the text's complex evocation of America's racial predicament. For example, Forrest G. Robinson sees a depth to Jim that he thinks previous scholars have missed. Jim is both the stereotypical "darky" and the complex human being, wearing a mask of contentment and gullibility that represents the kind of prejudice whites have about him as an African American. But behind the mask, the real Jim is a shrewd agent in his own defense. In essence, Robinson argues that whether Twain was aware of it or not, Jim is a complex African American character that reflects the situation of slaves at the time as they attempted to survive in a racist society. Such readings draw attention to the complex ways the novel addresses, in Robinson's words, "the nation's most painful and enduring dilemma." These readings accept Twain's ambivalence and contradictory responses to the issue, rather than attempting to vilify the author or insulate him from accusations of racism. In a related vein of argument, Peaches Henry declares that we may not be able to decide once and for all whether the novel is racist or subversive, but the book deserves our attention because "[t]he insolubility of the race question as regards Huckleberry Finn functions as a model of the fundamental racial ambiguity of the American mind-set."