Every little bit helps! Although some people did not make the connection between the evils of slavery and the characters in the book, it hopefully made them stop and think. It was also a tool for abolitionists to humanize the cause.
Harriet Beecher Stowe wrote a novel that shocked her public and evoked great sentiment toward the abolitionist movement. While there were cases of such terrible abuse of slaves, Stowe's hyperbolic presentation stirred those who were looking for justification of attack upon all who owned slaves.
The book was probably one of the most controversial publications in American history. Indeed, the historic importance of the book rather than its literary merits are reason it is still read today. The book brought slavery home to Americans. Southerners strongly denounced the book, but it called apathetic Northerner's to action by appealing to their Christian duty to end the moral wrong of slavery. The book caused such an outcry both against slavery in the North and against Abolitionists in the South, that when Lincoln actually met Harriet Beecher Stowe, her referred to her as "the little lady who started this great war" (see reference below). The book brought attention to Slavery not only within the U.S., but also created a furor abroad. It gave rise to calls from England for the end of slavery. Overall, Uncle Tom's cabin was a powerful political statement and brought the controversy over slavery to the boiling point.
Stowe did an eloquent and masterful job of pointing out how slavery destroyed families, foremost. The idea that even slave families should be kept together is a predominating factor in this selection. And while the novel is perhaps best celebrated as an abolitionist view of the slavery topic, questions are raised within the text that allow the pro-slavery supporters to assert that not all aspects of slavery were negative.
For instance, pro-slavery individuals could point to Mr. Shelby or St. Clare as exemplars for "the kind master." The fact that some masters were nicer than others, however, did not alter the fact that one human was owning another; the inherent flaw in the idea of slavery, according to Stowe. Public sentiment toward the slavery topic was swayed by this text because of its frank treatment of the matter at hand -- Stowe shows the slave lifestyle, warts and all. And whether she is revealing the better times or the worse, in the end, her novel drives home one final point: slavery was indeed wrong.