I may not be quite as precise in my wording, but there were many references in the several ordinances of secession of the several southern states that referred to the concept that since the Northern legislators were willing to violate the "Contract" (The Constitution) that they felt no binding arguement by which they were compelled to remain in that Union.
Lincoln on the other hand said that he would be President of all the States or none. THAT is the statement of a dictator. That without regards to the legality of his actions his intent was that he was willing to start a war in order to keep a people from exercising their legal rights. That had nothing to do with slavery and its rightness, or wrongness.
Therefore secession and the right of the states to exercise that right was the cause of the war. This is unique to the United States only. Since whereas in no other case of rebellions or other forms of unrest, resulted in the freeing of a slave populas, were the slave holders empowered with the right to withdraw, as a political entity, from their home country.
The Southern States secession was not rebellion under the Constitution because the southern states did not attempt to overthrow the Government of the United States. They simply withdrew as being a part of that government. A right not specifically enumerated as being prohibited in the Constitution and therefore permited under the 9th Amendment.
The Constiution would probably never have been ratified in 1787 had in not been for the addition of the 9th and 10th Amendments to the Constitution, given the difficulties of the definitions of Liberties among the 13 originals states under the Articles of Confederation. Differences that caused the breakup of that form of United States government, and making it necessary to form a "More Perfect Union".
Most people do not reailze that there was a United States before the Constitution, and that the Constitution did not simply drop out of thin air. George Washington was not the first United States President. He was the first under the NEW Constitution. There were fourteen previous Presidents of the United States before him during the 10 years under the Articles of Confederation. Why so many?
This country has already failed once in 1787, and again in 1861. What emerged after the second revolution in 1865 was not what our forefathers had in mind. We returned to being European again where the bureaucrats, starting with reconstruction, determine your Liberties.