It would be better to see an educational documentary or something to come to your own conclusions, but if you DO want to see it, I would recommend watching it for the same purpose. I'll probably watch it at some point.
We have to weigh out the positives and negatives related to Lincoln's presidency. In addition to his war mongering and racism, he DID try to get rid of the central bank and though the war sucked, it(along with the reparations) provided an equilibrium which put a quicker end to slave owning cronyism. Ron Paul said the government could have bought the slaves, and I don't know whether the congress would have agreed to that, but that would have been a more peaceful means to an end.
Civil rights have everything to do with libertarianism, so it would do a lot of good for us to write about it in a more positive light and about the things we COULD do, rather than more and more about the failures of what has already been done in the past.