Of course it was states rights. However, the only states right that was at issue was the right to own another person. Calling it a states rights issue is just a way to pretend it wasn't about slavery.
Let's say that, yes, the war was about the State's right to slavery.
I think the thing most folks forget, is that this right was written into the
Constitution. It was an institution that was not only in the South, but one that had been in the North, nor was it expressly illegal in the north, but was being phased out.
The problem with public education and mass media is that people today make the assumption that WAR and violence were the only way to get rid of the institution. They don't realize that many in the South were already looking to end the institution. The war did more harm to race relations and the cause of liberty than it did to help. Every other Western nation dealt with the problem peacefully.
Federal apologists just can never admit that the Jack booted thugs of the federal government were in the wrong for not respecting the Constitution of the United States. Was slavery part of the Constitution or was it not? Could this issue have been dealt with peacefully or not? The answer to both of these questions is a resounding yes. But international interests were afraid of how powerful the US was becoming, their agents agitated the States and provoked the war.
How the West (Except for the U.S.) Ended Slavery
How the West Ended Slavery LewRockwell.com
"Some people have objected that the United States couldn’t have bought the freedom of all the slaves, because this would have cost too much. But buying the freedom of slaves was not more expensive than war. Nothing is more costly than war! The costs include people killed or disabled, destroyed property, high taxes, inflation, military expenditures, shortages, war-related famines and epidemics . . . . The billions of dollars of Union military expenditures during the Civil War would have been better spent reducing the number of slaveholders and slaves, accelerating progress toward total emancipation."
Perhaps the one single passage that is Powell’s most incendiary is this one on page 241: "Slavery was being eroded throughout the West by political trends and relentless agitation. The process would have continued and perhaps accelerated without the Civil War."
To back up this statement, Powell argues that peaceful secession would have neutered the federal Fugitive Slave Act (which Lincoln strongly supported), creating a flood of runaway slaves that could not have been stopped and would have broken the back of the slave system. Echoing Spooner’s arguments, he also says that the Confederacy would have been politically isolated by the rest of the world so that "there would have come a time, much sooner than most people might expect, when the combined effects of multiple antislavery strategies would have brought about the fairly peaceful collapse of Confederate slavery. If this seems doubtful, just recall how a combination of pressures led the mighty Soviet Union to collapse and vanish from the map — without a (nuclear) war."
Powell concludes that blacks in America would have achieved freedom and justice much sooner had emancipation been peaceful, as it had been in most of the rest of the world in the nineteenth century.