Huck Finn the racist novel

Since the day Huck Finn was published it has been very controversial over three main topics. Is is racist, should it be taught, and is it a good book. Yes it a racist book, but at the same time it is a cornerstone of American literature and should be taught in classrooms.
Mark Twain wasn't trying to write a book that had so much controversy over it. He wasn't trying to write a racist book, but he did. The start of the book is racist. We see Jim demeaned and tricked by a dumb and stupid white boy named Tom. We don't see Jim as a human in the beginning, but rather a property of Miss Watson. Then again on Jackson's Island, Huck tricks Jim by a dead snake in his sleeping area because Jim thinks snakes are bad luck. Jim ends up being bitten for this. The final trick we see is when Huck and Jim get separated by the fog, Huck, when he finds Jim again says that it was all a dream. These three tricks demean Jim below the level of a normal human, and he is pitted as stupid. In those days a slave owner would never just free a slave, so we see that as racist towards Jim's part because that would never happen.
Now we do see Jim become a character along the river, and we see Huck grow and develop his own morale's. But this is all to be depleted at the end when Jim is once again, shoved below the dumb white boy Tom, and Huck's growth is stinted. This does bring us back to where we started, even though Jim is free, he is demeaned and pushed below humanity. Jim grows and becomes a true human, but then that is all diminished at the end. That is Jim's greatest blow, because now he is once again a dumb black man.
Yes this book maybe racist, but it is still a cornerstone for American literature. We see a boy deny the norms of society to do what is right. In this regard we have to put aside the ending. The whole river scene, we see a friendship grow between a boy and an adult, and we are able to see then growth off and with each other. Huck even admits he "go to hell" to try and help Jim get freedom.