Well, if slavery goes away peacefully and African-Americans/former slaves are at least considered human and citizens (actual civil rights, no Jim Crow are other issues) and new states are admitted as free and not forced slave constitutions, then no reason at all. While some southern/slave states would probably be willing to see slavery go away in the near future (that is not too long after 1860), and would also be OK with no slave:free admission formula, many southern states and their influential political/social elites would not buy this. If ending slavery was amenable to a peaceful solution in 1860, or in the 10-15 years thereafter there would not have been a civil war, sadly this was not the case.
The idea that there would be civil rights and no jim crow in the post-civil war era enters into the realm of ASB. Everyone on the board can tell you how
evil® the south was, but too many forget, conveniently that their own great-great-grandparents in Indiana or New York were just as bad as the
evil Southerners® when it came to civil rights for their fellow American who had the misfortune to have different skin pigmentation.
I think one way that the civil war
could be avoided is if the boll weevil arrived in the south about 60-70 years earlier, because the price of slaves were largely tied to the price/production of cotton. But to the issue of the latest time that the civil war could happen, I would say either sometime between 1864 and 1872. The reason for this is that I think that the civil war was inevitable (with the caveat of some agricultural disaster, like the boll weevil) once the Whigs collapsed and the Republicans gained in power. Had the Democrats been able to put a unified ticket together in 1860, the south would not have been likely to secede, at least at that time. But a Republican like Lincoln or Fremont winning the election in 1864 or 1868 would trigger the south's knee jerk flinch of secession.
The north's growing economic power and the industrialists determination to break the power that the plantation owners in the south was going to add fuel to the fire, and the Southern planter class was certainly willing to add their fuel to the fire to maintain their own balance of power.
Let's assume that the country gets to 1872, even w/out the civil war, the balance of power would have skewed so much more to the north's side, that saner heads in the south would have seen the futility (and before anyone jumps in an says,
but the south was EEEVIL. let me say, They were wrong, but they were not stupid. They seceded in 1861 because they didn't see the balance of power as being so out of whack. Hell, they had 3-4 billion dollars in economic might, wrapped up in chattel slavery, so they thought that they had the economy in 1861 to win a secessionist fight. They were wrong.
anyway, that's just my $0.02
