That not true. Mississippi and South Carolina were the first two states to file declarations of succession in 1860 and each did so listing their primary cause as that of Slavery. Their intent was to continue the practice despite what congress felt. The other reason was because of tariffs congress placed on imports from England to protect American manufacturers located in the northern industrial districts. Southern planters intended to band together to nullify Congress actions in placing tariffs on imported goodsThe Civil War was fought because we had an overbearing Federal Government trying to force their people into giving up States Rights. slavery was only one of them. It seems we are in the same situation about now. Time to lock, and load.
The Declaration of Succession are available online at each of the State's archives for review by anyone that has an interest.
Combat operations didn't start until April 11, 1861, Beauregard ordered the barrage on Fort Sumter.
Every attempt to obstruct and nullify congressional legislation today has been tried by the southern region of States in the united states before in our history. The southern region has long carried the resentment from having been beaten into submission and forced into recognizing and respecting human rights and the letter of the U.S Constitution.