Incorrect; Yes, it was a big issue for the south, but NOT in the way that you imply it to be as the sole cause of secession.
Slavery was not the issue that cause the south states to seceed. It was the abandoning of the rights and protections of the Constitution that caused the southern states to seceed. Not all slave holding states seceeded. So how could slavery be the cause of secession? Why did not all the slave holding states seceed, if that were the cause?
Not one states seceeded solely because of slavery. One state, South Carolina, seceeded because of the election of Abraham Lincoln and what was precieved as election fraud and the threaten aims of the Republican party, which was the unconstitutional abolishion of slavery. Ten other states, two "border" states, and three territories seceeded because of the unconstitutional use of United States Military Force by Presidents Buchanan and Lincoln.
More correctly slavery was the issue which cause a "crisis of confidence", among the Southern States, with the United States Government, that the restriction placed upon the United States government under the Constitution and United States Supreme Court decisions, in regards to States Rights and personal property rights, would not be repected.
That is what I am talking about the "slavery Issue" blanketing all other concerns in determining the real causes of the War. Take out the Slavery issue and you have a whole differene argument. True the "Crisis of Confidence" in the United States Government was generated by the debate over slavery. But that debate was Unconstitutional because of
Article IV, Section 2, paragraph 2,
"No Person held to Service or Labour in one State, under the Laws thereof, escaping into another, shall, in Consequence of any Law or Regulation therein, be discharged from such Service or Labour, but shall be delivered up on Claim of the Party to whom such Service or Labour may be due." This was Repealed by the 13th Amendment AFTER the War.
The 4th Amendment,
"The right of the people to be secure in their persons, houses, papers, and effects (which would include slaves as property), against unreasonable searches and seizures, shall not be violated,"
The 5th Amendment,
"No person shall *** be deprived of life, liberty, or property (which would include slaves), without due process of law; nor shall private property be taken for public use, without just compensation."
The 9th Amendment,
"The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people."
And the 10th Amendment.
"The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people."