Ajsalium wrote:So the American Civil War was a consequence of Scot and Irish temperament.

States' Rights was a later invention. The secessionists weren't that concerned about parts of States that wanted to remain loyal and even went so far as to pack the local legislatures with their confederates and even use force to intimidate pro-Unionists. Then there was the issue of Federal properties scattered throughout the South that was assumed would revert to the individual States, so no such thought was given to it, not even compensating for Uncle Sam for those places he'd paid for years ago, kind of like what a bunch of other St. Andrews Cross flag wavers are entertaining now.
Prior to the election of Lincoln, most US Presidents hailed from the South and government offices and Congress and the Senate were packed with Southerners. The Mexican-American War was due to Southern desire for territorial expansion and there was opposition to it at the time, from Lincoln and Grant, though a participant, denounced the causes. Southern influence was so great, that at one point the New England States were considering secession.
Rapid Northern industrialization, with a shift to big business influence, led to Southern fears of being reduced to the status of an exploited agricultural colony, like India or Ireland, where foreigner "Yankees" would dictate the prices. With the election of someone who wasn't one of their own and wasn't particularly sympathetic, tensions began to rise.
While slavery was an issue, it wasn't the cause, as a sort of compromise, like in prior instances, could be eventually reached, usually to the advantage of Southerners. The Border States, where slavery was declining, still made plenty of money off the trade with their Southern neighbors, but remained loyal in 1861 and even fought off encroachment prior to 1st Bull Run. Despite claims of Yankee aggression, there were attempts to grab neighboring territory and send troops to those parts refusing to secede: West Virginia, due to its location was able to maintain its independence, but attempts by Eastern Tennessee, roughly the location of the failed US State of Franklin, was again stamped out.
Lincoln's Emancipation Proclamation didn't affect the Border States and those areas occupied by Federal forces, but was intended for those areas in rebellion - the right of the conqueror. Complete emancipation wasn't a plan til the 1864 election, with Lincoln pressured by the abolitionists.
Had the Southerners kept their cool, they wouldn't have had to secede, as Lincoln wasn't going to take away their slaves, but once they had seceded, had they not made the first belligerent moves, before Fort Sumter, Lincoln might not have had the support to prosecute a war. An undermanned Fort Sumter wasn't threatening access to Charleston Harbor and even if the various State governments couldn't reach a compensation agreement with the Feds, unless the locations were used as staging posts for attack, in which case Lincoln would come across as the aggressor, the areas could be ignored by the locals.