It has presented a very complex portrait of slavery, with some slaves seeming happy with their lot while others (the ones I understand more readily) make repeated attempts to escape or buy their freedom. And some of the things the slave owners do and say seem rational, while others seem horrible. Some of the story is from the perspective of the slaves, some from the perspective of free blacks, some from the perspective of slave owners -- all with an omniscient narrator -- so it's never simple.
Thus far (about 3/4 of the way through), there's been one plot point that has upset me, when a free man was sold into slavery. I'm not sure why that bothers me so much more than characters who have always been slaves. I would say it seems like an injustice for him to be sold back into slavery after he had spent years earning the money to buy his freedom, but all slavery is injustice. I guess I'm buying in to the difference between slave and non-slave on some level. Reading this book is like being immersed in that world, so I'm not surprised it's affecting the way I see things. The way I read -- jumping into a book and then rarely coming out until I've finished -- probably strengthens the effect.
Speaking of which, off I go to read more.