“We began to stir against slavery. Hearts grew soft, here, there, and yonder. There was no place in the land where the seeker could not find some small budding sign of pity for the slave. No place in all the land but one—the pulpit. It yielded at last; it always does. It fought a strong and stubborn fight, and then did what it always does, joined the procession—at the tail end. Slavery fell. The slavery text remained; the practice changed, that was all.”

Source: Cannibals All!, or Slaves Without Masters (1857), pp. 307-308

Part I, CH 2: Chamberlain, p. 32
The Killer Angels (1974)

Interview with Associated Press http://www.morningsun.net/stories/120803/usw_20031208026.shtml December 2003

Both American and British abolitionists assumed that an end to slave imports would lead automatically to the amelioration and gradual abolition of slavery.
The Problem of Slavery in the Age of Revolution, 1770-1823, page 129. https://books.google.com/books?id=9lsvDwAAQBAJ&pg=PA129

Source: 2010s, Why the Left Hates America (2015)

As quoted in Report of the Joint Select Committee.

To Otto von Bismarck in June 1878, as quoted in Around the World with General Grant http://www.granthomepage.com/grantslavery.htm (1879), by John Russell Young, The American News Company, New York, vol. 7, p. 416.
1870s, Around the World with General Grant (1879)

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.

New England's Dead, reported in Bartlett's Familiar Quotations, 10th ed. (1919).