So many historical inaccuracies in this thread, where to start.
Since Grant is original post, I'll start there, it should be noted that Grant own a slave, possibly given to him before the war, and his wife, a Dent, inherited four slaves. They never freed them until slavery was abolished in December 1865. Yes, slavery was legal until the Constitution was amended in December 1865. The poster above is likely thinking of the ban on importing slaves, passed in 1808. Various individual states banned slavery, but the U. S. Constitution made slavery legal until December 1865.
Virginia, North Carolina, Tennessee, and Kentucky actually voted to NOT leave the union. The original seven that did vote to leave, only four mentioned slavery in their secession articles. Rhett Barnwell stated South Carolina's position was failure of some states to enforce the fugative slave act, nothing more. Texas, however, went on a racist bigoted rant, in theirs.
Of the four states that didn't vote to leave, two changed their minds later, specifically over states rights (yes, it was a real thing). Both Virginia and Kentucky are commonwealths, and like Texas, they specifically reserved the right to seceed when they joined the union. After Lincoln requested states send troops to furnish a 75,000 strong invasion force to invade the seven Confederate states, the right to seceed states balked at illegally invading another country, as it was legal for any state to seceed if they wish. The powers of the federal government are specifically spelled out, and it mentions anything not specifically reserved by the federal government is allowable to the the state to enact. Sucession was not prohibited until AFTER the war. So the seven states did legally seceed (which is why Seward advised not to pursue anyone for treason, and this let President Davis go free). With Lincoln not abiding by the constitutional allowance of any state to seceed, Virginia and Kentucky quickly seceeded, followed by stuck in the middle states Tennessee and North Carolina.
Btw, U. S. Congress authorized two official names for the war: The Civil War and the War Between The States.
Now the real reason for the war. Same thing as it always was since Calhoun's Nullification crisis. Unfair tariffs. The southern states were paying in approximately 70% of the federal budget but only receiving 30% in return. Slave produced goods accounted about 60% of the federal budget and 70% of total budget was going into northern infrastructure like railroads, canals, wharfs in New York, New Jersey, Philadelphia, Baltimore, etc. All built primarily with slave raised tariffs. When the south seceeded, it took 70% of the federal budget with it. Lincoln could not afford that, literally and politically. Hence the immediate blockade of southern ports and a planned invasion force.
Remember, slavery wasn't abolished until after the war. The northern troops were Union troops (restore the union) not anti-slavery troops. Many northern soldiers did join to fight slavery, and many southern soldiers were fighting for slavery. The 1860 census slave schedules show 91.5% of Confederate soldiers did not own a slave. The average Confederate soldier was not marching into cannon and musket fire so some rich plantation owner could own a slave. Slavery became an issue as a rallying cry after the north was getting beat up by the southern troops in the first two years of the war. The slaves were always intended to return to the fields after the war, to restore lost tariffs. Again, the abolishment was after the war was over, not before it started.
A lot of people are not aware of the Corwin Amendment. Thinking slavery was a greater issue than it really was, Lincoln supported the Corwin Amendment, pushed it through congress and got it passed, and got four states to ratify it. But before getting the needed number of states, the Confederate States declined the offer. What was the offer? In return for rejoining the union, the U. S. would essentially guarantee slavery forever to those states. Yet it was refused. Apparently, slavery was not the issue. Corwin Amendment, google it. Everything mentioned here is verifiable in real history books (collegiate level).
Btw, one other thing conveniently left out of high school history, the actual first shots of the war. Not Ft. Sumter, not even the cannon fire by The Citadel Cadets at the Star of the West on February 9, 1861. A day before, February 8. 1861 in Pensacola, Florida, Lt. Adam Jacoby Slemmer moved his company of infantry from Fort Barrancas, to the old abandoned star fort, Fort Pickens (War of 1812 era), property of the Confederate State of Florida (no standing lease) , and then ordered his company of U. S. Infantry to fire upon Florida Confederate Troops approaching the fort to inspect and secure it. Thus the actual first shot fired in hostility was fired by U. S. Troops. Slemmer was rewarded by being promoted to Brigadier General by war's end despite no further noted action. A New Yorker, Slemmer died in 1868, and the New York Times obituary, in bold headlines, stated he ordered the first shots of the war.
That's enough for now, but some won't be satisfied with this easily verified truth.
So many historical inaccuracies in this post. Where to start?
90% of this is irrelevant to the point. So I'll start at the point.
The Morrill Tariff didn't start the secession from the Union. It was adopted March 2, 1861 after most of the slave states had already seceded from the Union, meaning that the very Congressmen who could have voted the tariff down, had already vacated their authorities. None of the southern conventions in 1860 made any mention of the tariff. This is a Lost Cause myth.
The Corwin Amendment. Is this your version of the Morrill Tariff? You have a rather cute, quaint, and amusing perception of how the Corwin Amendment came about. If only you could actually read.
Abraham Lincoln did not "support" the Corwin Amendment, "push" it through congress nor "got" it passed. The Amendment was proposed by Congress on the same day that the Morrill Tariff above was adopted - March 2, 1861.
A sitting United States President has no role nor authority in the amendment process of the Constitution. Sorry about that. But at least you're better educated, now. The Corwin Amendment was actually endorsed by President James Buchanan, who preceded Lincoln. Buchanan even signed his name to the Congressional joint resolution, but as far as the Constitutional law is concerned, his signature is nothing but decoration.
The Amendment was already passed by Congress when Lincoln took over, and all he did was essentially say, "its constitutional law now, so I have no issue with it". I guess you could say that was "support", but I wouldn't.
But as with the Morrill Tariff, the Corwin Amendment came after Democratic representation from the slave states had withdrawn. After having essentially removed themselves as state members of the Federal Union, they forfeited their constitutional right to vote on any legislature.
So NO, the slave states did NOT "refuse" to vote on the Corwin Amendment, because they were no longer eligible voters when the Corwin Amendment was finalized by March 2nd, 1861....