Bullshit. Despite a considerable amount of after-the-fact historical revisionism, the South was EXTREMELY clear that they were seceding primarily because the North wanted to abolish slavery, and they didn't.
And since I wouldn't make such proclamations without evidence:
From Confederate Vice Present Alexander H. Stephens' "Cornerstone Speech" a few weeks before the Civil War:
"The new Constitution has put at rest forever all the agitating questions relating to our peculiar institution—African slavery as it exists among us—the proper status of the negro in our form of civilization. This was the immediate cause of the late rupture and present revolution. Jefferson, in his forecast, had anticipated this, as the "rock upon which the old Union would split." He was right. The prevailing ideas entertained by him and most of the leading statesmen at the time of the formation of the old Constitution were, that the enslavement of the African was in violation of the laws of nature; that it was wrong in principle, socially, morally and politically. [...] Those ideas, however, were fundamentally wrong. They rested upon the assumption of the equality of races. This was an error. [...] Our new government is founded upon exactly the opposite ideas; its foundations are laid, its cornerstone rests, upon the great truth that the negro is not equal to the white man; that slavery, subordination to the superior race, is his natural and normal condition. This, our new government, is the first, in the history of the world, based upon this great physical, philosophical, and moral truth."
From the South Carolina Declaration of Secession:
"The General Government, as the common agent, passed laws to carry into effect these stipulations of the States. For many years these laws were executed. But an increasing hostility on the part of the non-slaveholding States to the institution of slavery, has led to a disregard of their obligations, and the laws of the General Government have ceased to effect the objects of the Constitution."
From the Mississippi Declaration of Secession:
"Our position is thoroughly identified with the institution of slavery--the greatest material interest of the world. Its labor supplies the product which constitutes by far the largest and most important portions of commerce of the earth. These products are peculiar to the climate verging on the tropical regions, and by an imperious law of nature, none but the black race can bear exposure to the tropical sun. These products have become necessities of the world, and a blow at slavery is a blow at commerce and civilization. That blow has been long aimed at the institution, and was at the point of reaching its consummation. There was no choice left us but submission to the mandates of abolition, or a dissolution of the Union, whose principles had been subverted to work out our ruin."
Florida's declaration of secession was a simple statement with no mention of causes, but John C. McGee, president of the Florida convention that voted on secession, said at the convention:
"At the South and with our people, of course, slavery is the element of all value, and a destruction of that destroys all that is property."
Several other states' declarations, while making no direct mention of slavery as a cause, referred to joining with "the other slave-holding states."
So when you try to say that slavery only came into play as the last act of a desperate President Lincoln... Well, as Thepersona put it, you can just fuck right off.