Yeah, what's up with that? 
Finally came a couple of days ago. I've been reading the Civil War article.
I've seen, and also enjoyed, the Daniel Day-Lewis Lincoln movie.
I'm a little vague on this, but my feeling is that Lincoln, though presumably favoring abolition, was not a big anti-slavery crusader as much as a leader trying to find compromises that would keep the country together. That's shocking from today's perspective, but it's hard for us to put ourselves in the mindset of a time when slavery had been practiced so long and so routinely that it wasn't regarded as the great evil we see it as now. Maybe more like the way now we'd regard some people not having health insurance or something like that. Far from ideal, but maybe at the time considered short of outright evil.