During the Restoration, there was a tendency to rewrite Shakespeare plays to have happy endings or for other reasons.
It's normal for cultures to adapt materials to suit themselves. I don't really a problem with that. But it's one thing to create an adaptation. It's quite another to suppress the original.
When I was an English teacher, I used to teach Huck Finn to juniors. As you may know, one of the big objections to that book is the use of the N word. I actually wouldn't have minded the substitution of a different term for high school use. I have been unhappy, however, with later attempts to ban the book. They're rooted primarily in a misunderstanding of what Twain was trying to do.
Twain was writing in 1884 for an audience that wasn't especially racially enlightened--to put it diplomatically. His own sensitivity to racial issues was, by his own admission, a work in progress. He grew up in pre-Civil War Missouri, and there is a large autobiographical element in books like Tom Sawyer and Huck Finn. In later life, Twain admitted to being uncomfortable when white people waited on him. He had other issues adjusting to new realities as well. But he recognized his reactions for the shortcomings they were and worked to change them.
What's the best way to get a bigot to realize the error of his ways? The stealth approach--you sneak the message in, rather than making it too obvious at first. That's exactly what Twain does in HF. Jim, Huck's slave friend, starts out as a figure of fun who is often the butt of the joke. Black characters would have often been portrayed this way at the time. When Huck, who has run away from his abusive father, encounters Jim again and realizes Jim is now runaway slave, he wants Jim to turn himself in. Much later in the book, when Huck has had time to realize the truth of Jim's situation and to appreciate their common humanity, he tells himself that he's going to help Jim escape instead of turning him in. He's been taught that helping an escaped slave means going to hell, and he says if that's what has to happen, he'll go to hell to help Jim.
As for Jim, he evolves from the butt of the joke to a father figure for Huck, far superior to his white biological father. In fact, Jim puts his own life at risk to save Tom Sawyer after Tom has been shot. Morally, he ends up being the best person in the whole book.
How many bigots Twain actually converted might not be possible to determine, but he does all he can to shift our sympathies toward Jim and away from the society that is ready to condemn him. Banning the book deprives students of the opportunity to see how prejudices are sometimes overcome in the real world. It also cuts them off from Twain's real-life attempt to redeem himself.
