It was the top-selling fictional book of the 19th Century (and second-best period - behind only the Bible), and many of the black characters nece the stereotypes of black characters seen in media even today. Mammy, black waif child, and Uncle Tom included.

Uncle Tom was meant to be an almost Christ-like figure by Stowe. But in later years people came to view him differently - often due to state plays of the story that changed the story to give Tom a "happy" ending.

Now when people refer to an "Uncle Tom" they're referring to a black man who not only allows himself to be mistreated, but actually loves his masters. Someone whose subservience and loyalty amounts to complicity with the mistreatment of himself and others.

In the book, he is kind and peaceful, and the entire books has a theme of goodness prevailing over violence.

The slave hunter sent after Eliza and her family shot in the book, and instead of letting him die they take him to a Quaker community that helps him recover. Through the kindness shown by the escaped slaves and the Quakers he learns to understand what goodness is, rejects slavery and prejudice, and helps the escaped slaves flee to Canada.

Tom's kindness inspires a slave-owning family to reject slavery and prejudice (2 different evils addressed by the book). His tragedy is that the sister of his owner that intended to free him sells him off to Simon Legree - the most purely-evil slave master in the book.

Tom is later mortally beaten, but forgives those who are killing him (it's not subtle at all about the comparison to Christ), and afterwards the men who did it once again reject slavery.

But later adaptations, especially plays and "anti-Tom" literature paint him as an obedient, happy slave that is perfectly content to be abused and watch other be abused. That combined with readers confusing peace and kindness with embracing evil has lead to a tragic misinterpretation of a character meant to outrage people and put a magnifying lens on the evils of slavery.

And it worked. Legend says that when Harriet Beecher Stowe met President Lincoln in 1862, he said "So you are the little woman who wrote the book that started this great war."