Has anyone noticed that Kansas is now a slave state TTL?
It's not going to be popular of course - but I see a civil war happening in it like in Missouri.
OTL was bad enough, TTL I don't know if I want to read how bad it's going to get during the Buchanan Administration. If Brenckinridge is still his VP, he is going to have so many problems in his administration it's going to make Pierce seem... well, okay, average. Won't quite make Pierce look good, but still...
As for Kentucky, OTL Lincoln said the Union must have it to survive, but I wonder if it'll be tempted to secede, too.
As stated above, though, the Union won't be fighting with one hand tied behidn its back this time. Fremont was relieved in Missouri for freeing slaves with his army, but he might not be TTL. In fact, THe Pathfinder might be told "If you want to do that, do it in Kansas," which wasn't supposed to be slave to begin with. We might see him continue as a general, which would create interesting butterflies itself. Fremont and Grant combining to march down the Mississippi? Or, more interesting, maybe Lincoln doesn't have the patience he did with McClellan OTL when McClellant lollygagged around in late 1861-early 1862. Maybe he'll replace McClellant early, before his disaster of mid-1862. Not that Fremont would necessarily replace him, but the chances of Fremont remaining in a meaningful command are much greater.
Of course, another possibility is that the South secedes early, they kept threatening to and I would imagine they do so more here than OTL, though I'm not sure. However, a more hevily Republican Congress in 18i58 might make thigns hard enough for Buchanan that he caan't do anything about their plans, and if they override a veto (such as repealing a Fugitive Slave Act early in 1860) you might see the South secede months earlier than OTL.