The problem with that is that the Southern states' only complaint about states' rights that actually matters (i.e., isn't either a blatant lie, complete bull****, or both) has to do with slavery. And besides which, their own vice president explicitly admitted the whole thing was over slavery, as I quoted earlier. The idea that the war was ever about states' rights at all came afterwards.
Anyway, it looks like only four states actually bothered putting together the reasons for their secession in a single document:
Mississippi,
Georgia,
Texas, and
South Carolina. I've looked at the statements of the others, and they're just legal stuff about how they voted for secession: "Blah blah we secede blah blah union dissolved blah blah the North sucks."
Mississippi doesn't say much of interest; they start talking about how awesome slavery is and how terrible it is that the North wants to end it in the second sentence and never stop.
Georgia goes off the deep end. In one sentence, they actually complain about the government paying for lighthouses and subsidizing fishermen. They also spin some weird conspiracy theory about how the North is waging total economic warfare on them and using the federal government to do it. They proceed to connect to the abolitionist movement in the North (what?) and essentially say that the Republican Party is a result of this grand economic conspiracy (what?). After this little jaunt, they mostly rant about the North doesn't support slavery, none of the Northern states are complying with the Fugitive Slave Act and thus are in abrogation of their Constitutional responsibilities (which, I suppose, is technically true, but I'm not blaming them for it), and talk about how mean and terrible it is that slavery is forbidden in the territories.
Texas explicitly admits that they subsumed themselves into the US when they were (willingly) annexed, and maintains that they were explicitly admitted as a slave state, which is true. They then have this to say:
"The controlling majority of the Federal Government, under various pretences and disguises, has so administered the same as to exclude the citizens of the Southern States, unless under odious and unconstitutional restrictions, from all the immense territory owned in common by all the States on the Pacific Ocean, for the avowed purpose of acquiring sufficient power in the common government to use it as a means of destroying the institutions of Texas and her sister slaveholding States."
Say
what? This is a blatant ****ing lie, as should be immediately obvious. Of course, what they actually mean is that slavery was not permitted in any of the territories
bought conquered from Mexico in the Mexican-American war. That territory also wasn't "owned in common by all the States." It was administered and owned by the federal government. After this howler, they talk about Kansas and how bad the Northerners were there, when it was the Southerners who came in a rush to prevent Kansas from becoming a free state (Google "Bleeding Kansas" for more on that little episode). They didn't succeed there; Kansas was admitted as a free state. Anyway, they do actually have something that could possibly be a valid complaint in all this. They complain that the federal government hasn't done enough to secure the borders of Texas against Mexican bandit and Indian incursion. Of course, they then complain about how the government didn't pay them for their expenses in repelling these incursions. My guess is they asked, and got told "that's a matter for the state police. No, you aren't getting money from us for it." Most of the rest of the document is either complaining about how the North hates slavery, or is full of effusive praise of how awesome slavery is.
Now we get to South Carolina, the first of the states to secede. What do they have to say? They are in fact the only state that mentions states' rights in their Declaration of Secession, but pretty soon reveal that they were only talking about their right to own slaves. Every single grievance they list is in relation to slavery or the abolition thereof. As a subset of this, towards the end they also complain about the Republican Party, and how the duly elected President, Abraham Lincoln, (gasp!) opposes slavery, and has called for its abolition.
Also of interest may be
this page, which details the differences between the US and CSA constitutions, and has the texts side by side. The TL;DR is that the Confederate states only gained a few minor rights under the CSA Constitution, but the right to own slaves was put in in just about as ironclad language as possible in multiple places. The CSA Constitution does not modify the Supremacy Clause, Interstate Commerce Clause, or the Necessary and Proper Clause, which tend to be major sticking points for states' rights activists.
For those who claim that the Civil War was about slavery, explain why the Emancipation Proclamation didn't actually free slaves in the North. The side that supposedly were fighting to end slavery.
The Emancipation Proclamation was, at the time, largely a political move. Lincoln's only initial goal was to preserve the Union; there's a rather famous quote of his where he says that he would willingly let slavery continue if it would preserve the Union. Of course it wouldn't have, since at least for Georgia, one of the reasons for seceding was that a Republican President was elected at all.
Anyway, during the Civil War, there was great concern in the North over whether the so-called "Border States" would secede. These were, at first, Missouri, Kentucky, Delaware, and Maryland. West Virginia could be added to this group later; it didn't become a state until 1863, when it broke away from Virginia and returned to the Union. All three of the original border states were slave-holding, and Lincoln could not risk alienating them and potentially driving them to the Confederacy,
especially Maryland. Washington, D. C., you may remember, is on the border of Maryland and Virginia, and was thus directly across the river from enemy territory. Had Maryland decided to secede, the Union capital would have been surrounded, and its position completely untenable. This probably wouldn't have resulted in the end of the war, mind, but it would have been a great blow.
It wasn't until later in the war that Lincoln came to believe that freeing the slaves was a worthy war aim in and of itself; he had begun to change his position before writing the Emancipation Proclamation, but IIRC he had not yet fully come around to the hardline abolitionist point of view (he initially favored a slow phasing out of slavery over several decades, as I recall). The Emancipation Proclamation also served to placate the abolitionists as well, began to shift the North's war aims towards total abolition, and also may have helped dissuade any European power from intervening on the Confederates' side.
Wiki actually has a pretty good article on the whole subject.
In short, the South seceded almost entirely because of slavery, while the North then proceeded to fight a war the South started to preserve the US and suppress the South's rebellion. Only later did the war end up becoming about slavery as well for the North.
Edited for spelling.