Even Shelby Foote has recognized that and said so:
Shelby Foote
https://www.c-span.org/video/?c4454375/author-shelby-foote-meaning-civil-war-us-history
St. George Tucker’s Jeffersonian Constitution
A really good piece on the subject you might enjoy @Smokin Joe.
Thank You @ Bigun. My ancestors signed an oath to the Sovereign State of Maryland between the Revolution and the Constitution's ratification. To me, that clarifies the nature of the Compact, in that one was a Marylander, Virginian, Pennsylvanian, etc., first, and a Citizen of what were then described as "These United States" second (As opposed to "The United States"). The clear implication of the former being that several Sovereign States were united for the purpose of mutual defense, trade negotiations, mail, and policies, a common currency, weights, measures, etc., with some limited Federal Power to enforce and regulate specific areas and settle disputes between States, and not the National Government the Hamiltonians finally imposed which is implied by the latter.
That came after the military conquest of the Southern States which had seceded (and occupation and military domination of others) in the 1860s. That Americans were deeply divided in their belief as to how that government was to function vs the State and Local Governments is reflect in the intensity of that conflict, and the casualties inflicted thereby.
This also explains why so many fought when only one in four households in the South had one or more slaves, and fewer than 15% of combatants owned slaves. Even by the most amplified accounts, fully two thirds of the Southern troops had no direct or indirect interest in preserving the institution of Slavery, an institution which was doomed at any rate within a few decades.
In my home State (well, State of Origin, I'm transplanted, now) manumission was on the rise as crop types changed to support the dietary needs of the growing Federal District and the port and industry around Baltimore. As well, and noted, slaves were not allowed in the holds of ships being loaded (incredibly hazardous duty) because it would place a valuable asset at risk.
Keep in mind the value of those slaves owned often exceeded the value of the land and tools they worked with, including buildings. It was far cheaper to hire an immigrant for a pittance to do the dangerous work, and if they were killed, to pay off the widow (generous, that) and hire another--besides, the immigrants provided their own sustenance from their wages. (If you ever wondered why the Irish ended up being police, teamsters, firemen, longshoremen, miners, etc., well, now you know. The Irish were treated pretty shabbily.)
For those who did own slaves, sure, there was motive enough in resisting the forcible deprivation of fully half or more of their assets, without compensation, by government decree. Do that to anyone today, and they'd be up at arms, too--do that to the wealthiest 25% of a region, and it's
casus belli.
So, to be historically accurate, the reasons for any individual going to war likely varied, to fight for their home State, and its continued sovereignty, to fight to protect personal or family assets, to fight what had been seen as decades of oppression by northern interests, particularly industrial ones (which the South was building in the couple of decades leading up to the war), or very simply, to defend your home State against invasion by the Armies of other States. (I reiterate, the definition of Militia in Barclay's dictionary in the 1820s was:
The Army, in it's entirety, and each State had one.)
For those who believe in an Oligarchy, a deep state, a well funded cabal of special interests who exert disproportionate influence on policy, one might even be able to make the case that Abolition was pushed as an issue to provoke war, to destroy the budding industrial capability of the South before it grew enough to make the Southern source of raw materials for the Northern Mills independent of those same industrial interests and the region more self sufficient, even as the North retained domination of shipping, including the influx of immigrants from Europe, and especially Ireland).
The effects, from cultural condescension (continued even to this day with the whole Hillbilly Hick meme commonly embraced by some urbane Northerners and especially in the media) to economic exploitation that began with the carpetbaggers and continued until people and resources from other nations were cheaper to exploit, have been framed in the well-controlled accounts of history and the general Northern domination of the popular press as well, but aside from snide sanctimony, have also disparaged the contributions of those Virginians (Jefferson, Madison, et. al.) and others who framed the very fabric of this nation.
That is the lens through which our origins have been distorted into the origins of a Nation rather than a federation of united sovereign states, and in those distortions, much of the original intent of that compact (The Constitution) have been lost.