“Yankees are fond of citing Confederacy officials in support of slavery and a war for slavery. Most Southerners, however, were not slaveholders. All Southerners were sovereigntists, fighting a 'War for Southern Independence.' They rejected central coercion. Southerners believed a union that was entered voluntarily could be exited in the same way.”

James M. McPherson "James McPherson: What They Fought For, 1861–1865" https://web.archive.org/web/20160309201904/http://www.booknotes.org/FullPage.aspx?SID=55946-1 (22 May 1994), Booknotes, United States of America: National Cable Satellite Corporation
1990s

2000s, The Speech That Changed the World (2009)
Context: The South knew that it would never in future possess the same power relative to the North that it did in 1861. From that perspective, it was now for never or Southern independence, if slavery was to be preserved.

James M. McPhersonThis Mighty Scourge: Perspectives on the Civil War (2007), Oxford, New York: Oxford University Press. p. 188
2000s

Letter to Sir Austen Henry Layard (20 October 1861) on the American Civil War, quoted in Jasper Ridley, Lord Palmerston (London: Constable, 1970), p. 552.
1860s

Source: 1990s, For Cause and Comrades: Why Men Fought in the Civil War (1997), pp. 109–110
Context: It would be wrong, however, to assume that Confederate soldiers were constantly preoccupied with this matter. In fact, only 20 percent of the sample of 429 Southern soldiers explicitly voiced proslavery convictions in their letters or diaries. As one might expect, a much higher percentage of soldiers from slaveholding families than from nonslaveholding families expressed such a purpose: 33 percent, compared with 12 percent. Ironically, the proportion of Union soldiers who wrote about the slavery question was greater, as the next chapter will show. There is a ready explanation for this apparent paradox. Emancipation was a salient issue for Union soldiers because it was controversial. Slavery was less salient for most Confederate soldiers because it was not controversial. They took slavery for granted as one of the Southern 'rights' and institutions for which they fought, and did not feel compelled to discuss it. Although only 20 percent of the soldiers avowed explicit proslavery purposes in their letters and diaries, none at all dissented from that view. But even those who owned slaves and fought consciously to defend the institution preferred to discourse upon liberty, rights, and the horrors of subjugation.

1860s, Our Composite Nationality (1869)
Context: Southern gentlemen who led in the late rebellion have not parted with their convictions at this point, any more than at any other. They want to be independent of the negro. They believed in slavery and they believe in it still. They believed in an aristocratic class, and they believe in it still, and though they have lost slavery, one element essential to such a class, they still have two important conditions to the reconstruction of that class. They have intelligence, and they have land. Of these, the land is the more important. They cling to it with all the tenacity of a cherished superstition. They will neither sell to the negro, nor let the carpet-bagger have it in peace, but are determined to hold it for themselves and their children forever. They have not yet learned that when a principle is gone, the incident must go also; that what was wise and proper under slavery is foolish and mischievous in a state of general liberty; that the old bottles are worthless when the new wine has come; but they have found that land is a doubtful benefit, where there're no hands to till it. Hence these gentlemen have turned their attention to the Celestial Empire. They would rather have laborers who would work for nothing; but as they cannot get the negro on these terms, they want Chinamen, who, they hope, will work for next to nothing.

Source: 2000s, A New Birth of Freedom: Abraham Lincoln and the Coming of the Civil War (2000), p. 249

The Cause Lost: Myths and Realities of the Confederacy (1996)

Source: 2010s, Fateful Lightning: A New History of the Civil War and Reconstruction (2012), Chapter One