This is simple not true and not supported by the evidence at the time. After the southern rebellion was beaten they did change their tune and try to claim it wasn't about slavery but right before and during the war they were crystal clear that slavery was the reason they were rebelling. All other consideration were a distant second.\n\n"Then, the subjects of controversy between the two parties were merely questions of domestic policy, important it is true, but not vital; now, questions affecting our liberties as a people, and, it may be, our existence as a nation, are under discussion." (Emphasis mine)\n\n"Upon these questions the parties are arrayed, and the contest approaches. Upon the one side the Democratic party, buoyant with the recollection of many victories gained in the cause of the country; on the other Freesoilers, black Republicans and Abolitionists, consolidated and combined. These, sir, are the two great contending political forces that divide the country. All others are mere political atoms, that cannot and will not be felt, except so far as they may affect the contest between the two main organizations." (Emphasis mine)\n\n"Such, gentlemen, are the parties to the contest. The issue between them should be clearly understood, especially here at the South. I assert, and shall maintain it with the proofs, that this issue is, whether African slavery shall be abolished here in the States, where it now exists? Let us not be deceived upon this point. Men may talk about our rights in the territories, but depend upon it they are not the questions now in issue. The abolition of slavery here at home is the design of our opponents. This is the bond that cements all the anti-slavery elements in one solid column against us."\n\nMarch 9, 1860\n\nJohn W. Ellis Governor of Georgia\n\nIn view of such effects and consequences here from the mere possession of one branch of Congress we ought not to shut our eyes to the effects of the possession of the government in all of its departments by any Black Republican. It would abolitionize Maryland in a year, raise a powerful abolition party in Va., Kentucky, and Missouri in two years, and foster and rear up a free labour party in [the] whole South in four years. Thus the strife will be transferred from the North to our own friends. Then security and peace in our borders is gone forever. Therefore I deeply lament that any portion of our people shall hug to their bosoms the delusive idea that we should wait for some "overt act." I shall consider our ruin already accomplished when we submit to a party whose every principle, whose daily declarations and acts are an open proclamation of war against us, and the insidious effects of whose policy I see around me every day. For one I would raise an insurrection, if I could not carry a revolution, to save my countrymen, and endeavor to save them in spite of themselves. – Letter from Senator Robert Toombs to Alexander Stephens-February 10,1860\nThe anti-slavery party contends that slavery is wrong in itself, and the Government is a consolidated national democracy. We of the South contend that slavery is right, and that this is a confederate Republic of sovereign States.\n\n—Laurence Massillon Keitt (D-SC), Speech to the House, January 1860.\n\n\n\nWe recognize the fact of the inferiority stamped upon that race of men by the Creator, and from the cradle to the grave, our Government, as a civil institution, marks that inferiority.\n\n—Senator Jefferson Davis (D-MS) (29 February 1860)\n\nWe prefer, however, our system of industry, by which labor and capital are identified in interest, and capital, therefore, protects labor–by which our population doubles every twenty years–by which starvation is unknown, and abundance crowns the land–by which order is preserved by unpaid police, and the most fertile regions of the world, where the white man cannot labor, are brought into usefulness by the labor of the African, and the whole world is blessed by our own productions. All we demand of other peoples is, to be let alone, to work out our own high destinies. United together, and we must be the most independent, as we are the most important among the nations of the world. United together, and we require no other instrument to conquer peace, than our beneficent productions. United together, and we must be a great, free and prosperous people, whose renown must spread throughout the civilized world, and pass down, we trust, to the remotest ages. We ask you to join us, in forming a Confederacy of Slaveholding States.\n\n—Convention of South Carolina, Address of the people of South Carolina to the people of the Slaveholding States. December 25, 1860.\n\nOur people have come to this on the question of slavery. I am willing, in that address to rest it upon that question. I think it is the great central point from which we are now proceeding, and I am not willing to divert the public attention from it.\n\n—Laurence Massillon Keitt (D-SC), South Carolina secession debates. December 1860.\n\nBetter, far better! endure all the horrors of civil war than to see the dusky sons of Ham leading the fair daughters of the South to the altar.\n\nWilliam M. Thomson to Warner A. Thomson. February 2, 1861.\n\nThe South is now in the formation of a Slave Republic. This, perhaps, is not admitted generally. There are many contented to believe that the South as a geographical section is in mere assertion of its independence; that, it is instinct with no especial truth—pregnant of no distinct social nature; that for some unaccountable reason the two sections have become opposed to each other; that for reasons equally insufficient, there is disagreement between the peoples that direct them; and that from no overruling necessity, no impossibility of co-existence, but as mere matter of policy, it has been considered best for the South to strike out for herself and establish an independence of her own. This, I fear, is an inadequate conception of the controversy.\n\n—L.W. Spratt, The Philosophy of Secession: A Southern View. February 13, 1861.\n\nIsham Harris, Governor of Tennessee, January 7, 1861, (Messages of the Governors of Tennessee, p. 255); "The systematic, wanton, and long continued agitation of the slavery question, with the actual and threatened aggressions of the Northern States and a portion of their people, upon the well-defined constitutional rights of the Southern citizens; the rapid growth and increase, in all the elements of power, of a purely sectional party,..."\n\n\n\nHenry M. Rector, Governor of Arkansas, March 2, 1861, Arkansas Secession Convention, p. 44 "The area of slavery must be extended correlative with its antagonism, or it will be put speedily in the 'course of ultimate extinction.'....The extension of slavery is the vital point of the whole controversy between the North and the South...Amendments to the federal constitution are urged by some as a panacea for all the ills that beset us. That instrument is amply sufficient as it now stands, for the protection of Southern rights, if it was only enforced. The South wants practical evidence of good faith from the North, not mere paper agreements and compromises. They believe slavery a sin, we do not, and there lies the trouble."\n\nS. C. Posey, Lauderdale County, Alabama, speaking to the Alabama Secession Convention on Jan. 25, 1861: "Mr. President, the fierce strife we have had with the Northern States, which has led to the disruption of the Government, is a trumpet-tongued answer to this question. They have declared, by the election of Lincoln, “There shall be no more slave territory–no more slave States.” To this the Cotton States have responded by acts of secession and a Southern Confederacy; which is but a solemn declaration of these States, that they will not submit to the Northern idea of restricting slavery to its present limits, and confining it to the slave States."\n\nJohn Tyler Morgan, Dallas County, Alabama; also speaking to the Alabama Secession Convention on January 25, 1861: "The Ordinance of Secession rests, in a great measure, upon our assertion of a right to enslave the African race, or, what amounts to the same thing, to hold them in slavery."\n\nIsham Harris, Governor of Tennessee, January 7, 1861, (Messages of the Governors of Tennessee, p. 255); "The systematic, wanton, and long continued agitation of the slavery question, with the actual and threatened aggressions of the Northern States and a portion of their people, upon the well-defined constitutional rights of the Southern citizens; the rapid growth and increase, in all the elements of power, of a purely sectional party,..."\n\nI could literally post another 100 quotes on southerners themselves proclaiming slavery as the reason they rebelled. Even states that didn't mention slavery in their secession ordinances talk almost exclusively of slavery at their secession conventions.\n\n\n--------------------------------------------------------------------------------------------------------------------------------------------------------------------\n\nI only need two quotes to demonstrate why the war was fought;\n\n" “If I could save the Union without freeing any slave, I would do it;" - Abraham Lincoln, 1862\n\n"“to sustain a government capable of vindicating its just and rightful authority, independent of ni**ers," - William Sherman\n\nThe war had absolutely nothing to do with slavery, as you can see above.\n\nPS- Sorry, I had to edit Sherman's remark. It was so foul, hateful, and filthy, it would have been, quite properly, censored. I'm sure you understand. Thanks.