It is a common assertion nowadays that the Confederacy had no purpose or justification but perpetuating racist slavery.
That argument can be made intelligently, and has been made, but the lazy debater wants to treat it as a settled proposition above discussion. Any objection to it, or any suggestion of Southern legitimacy, is automatically dismissable because it amounts to a defense of the Confederacy, and even if someone who is not an outright racist or slavery-apologist would defend the Confederacy, the debater on the other side has the option to not be bothered with that distinction. Far easier to dismiss the opposition as crypto-racist.
It's the old fallacy of arguing in a circle. Yet people choose this tactic, perhaps in part because they find it frustratingly difficult to pin down American history or any part of it to such a simplistic idea as "it was all about slavery."
Naturally, some people do want to regard all this as settled before they plow into their opponents. The easy expedient is to go in search of one zinger of a quote that will seem to prove the case. In Internet debates, those willing to be convinced will look no further, and those who disagree will be required to build up the cathedral of context, a tedious process. By the time they finish, the audience will have wandered off with the zinger lodged in their heads.
So they pick through the sources. Any quote will do, by anyone remotely prominent in the Confederacy, saying, more or less, "it was all about slavery." Jeff. Davis's inaugural speech? No, it makes nary a mention of slaves or slavery. Robert Toombs' report to the Georgia legislature in 1860? No, that outlines how anti-slavery agitation in the North was exploited by political powers there to disguise economic motives.
The "Cornerstone Speech" by Alexander Stephens is the usual bludgeon of choice. Stephens, a Georgian who had served in Congress, was the new vice president of the CSA in the spring of 1861, and in this speech he explained the new Confederate constitution and the prospects of the new nation, as he saw them, to an audience in Savannah. Here is how one commentator cherry-picks the usual cherries from it:
Stephens said that the American Revolution had been based on a premise that was “fundamentally wrong.” That premise was, as Stephens defined it, “the assumption of equality of the races.” Stephens insisted that, instead, “our new [Confederate] government is founded upon exactly the opposite idea. Its foundations are laid, its cornerstone rests upon the great truth that the Negro is not equal to the white man. 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 and moral truth.”Stephens's post-war writings downplayed the importance of slavery in the sectional conflict, and they formed much of the foundation of the first generation of defense of the Southern nation -- the so-called "Lost Cause" view of the war. That reasonably can be dismissed as a convenient revisionism.
The Savannah speech exists in transcripts. There is no original version of Stephens's speech, because he spoke extemporaneously. His words were jotted down and printed in the Savannah newspapers. Stephens sometimes complained of the inaccuracy of such reporting, and singled out Savannah reporters in at least one instance, "who very often make me say things which I never did" [speech to the Georgia Legislature, Nov. 14, 1860]. But I have not found that he said at any time after the Cornerstone Speech that they got any part of it fundamentally wrong.
Stephens was educating the people of his state and preparing them for a fight he had tried to keep them out of. In the state legislature in July 1860, he fought hard against Georgia's call for a secession convention, then at that convention Stephens spoke out against secession so vehemently that the North circulated copies of his speech as propaganda during the Civil War.
The "Cornerstone Speech," in its praise of slavery, is a personal justification of Stephens's career. His post-bellum history book that downplays slavery's role ("Constitutional View of the Late War Between the States") is another. They both are public, political rhetoric. Yet commentators tend to treat the one as an utter lie and the other as absolute truth. To see the offhand paragraph in the speech as some defining Genesis moment of the Confederacy, out of the mouth of the eternal spirit of the nation instead of one political man, is a gross exaggeration.