An 1860 POD is way too late for most Midwestern states to adopt slavery. At most, some meddling might get a slaver victory in Kansas, but that would only galvanize the North even more.
TRH, the PoD is 1836
An 1860 POD is way too late for most Midwestern states to adopt slavery. At most, some meddling might get a slaver victory in Kansas, but that would only galvanize the North even more.
TRH, the PoD is 1836
Whoops, I forgot about that. Still, I'd maintain that the options are limited. 1836 is still too late for Illinois and Michigan, and I think geography rules out Wisconsin and Minnesota. Maybe you could get Iowa, Kansas and Nebraska this way, but only by throwing popular sovereignty out the window and somehow destroying the authority of the House of Representatives, which had a northern majority from the 1810's onward. People focus too much on the Senate in these times, but I don't think such a ridiculously pro-South arrangement could be gotten away with. Hell, the House nearly voted Arkansas a free territory back in 1819, for an idea of how radical they were even at that early date. So, I think Kansas and Nebraska getting "popular sovereignty" that's tipped towards slavery through wanton violence, plus some arrangement about the Mexican Cession south of the Missouri Compromise line is the best you could get through the Congress of the time. And even that adds additional problems in California, which didn't want slavery.
What if the USA annexes more of Mexico in 1848, bringing two or three new slave states for the south?