Somebody tell Cory...
Initial secessions were caused by belief that the Lincoln administration would try to abolish slavery. Hot heads in South Carolina ordered the US Army to leave Fort Sumter which they regarded as sovereign SC territory (in Charleston harbor). When the commander refused they were ejected by force (”firing on fort Sumter”). That action was the basis for Lincoln raising an army to force the rebellious states to return to the Union (”preserve the Union”) which, in turn, resulted in the raising of a southern army and the secession of most of the rest of the slave holding states. So the answer is that the penultimate cause was slavery, but the final cause, and the reason for starting the war was states rights (i.e., leaving the union... secession and state versus national sovereignty)
RedEyejack: "Initial secessions were caused by belief that the Lincoln administration would try to abolish slavery."
Correct, but our Lost Causers insist slavery was not the only issue, indeed was not even the main issue.
The "real reason" they say, was in our words: economic exploitation of the South by the North.
The South, they say, produced all the export revenues, the North, they claim, spent all the profits.
The truth is that's not what secessionists said at the time, but it doesn't matter to Lost Causers.
Secessionist documents are about 90% slavery, maybe 10% something to do with economics.
RedEyejack: "Hot heads in South Carolina ordered the US Army to leave Fort Sumter which they regarded as sovereign SC territory (in Charleston harbor). "
It would be more accurate to say those "hot heads" ordered Jefferson Davis to force Union withdrawal from Fort Sumter, one way or another.
RedEyejack: "When the commander refused they were ejected by force (”firing on fort Sumter”)."
Correct, though there are some interesting sub-plots to this story which our Lost Causers insist make it a very different narrative.
RedEyejack: "That action was the basis for Lincoln raising an army to force the rebellious states to return to the Union (”preserve the Union”) which, in turn, resulted in the raising of a southern army and the secession of most of the rest of the slave holding states."
Sure, except remember at the time of Fort Sumter the US Army totaled about 16,000 troops, more than half scattered in small forts out west.
Confederates had already authorized 100,000 troops in March and soon after Fort Sumter called up another 400,000.
So it was not until several months into the war that the Union side began to equal & surpass Confederate numbers.
RedEyejack: "So the answer is that the penultimate cause was slavery, but the final cause, and the reason for starting the war was states rights (i.e., leaving the union... secession and state versus national sovereignty)"
No, sorry, but the first, last & only major cause for secession was slavery and the immediate cause for war was months of Confederate provocations, their attack on Fort Sumter, their Declaration of War on May 6, 1861, their waging of war in Union states and their refusal to stop fighting on any terms better than Unconditional Surrender.
The rest is just Lost Causer smoke & nonsense.