New England Ships Freighted with Sable Victims
The radical and dangerous abolitionist doctrines of William Lloyd Garrison and his followers incited slave uprisings and race war in the South instead of advancing practical and peaceful solutions to the riddle of African slavery.  The Nat Turner massacre of innocent women and children in 1831 was a preview of what this radicalism would bring; the John Brown carnage in 1859 convinced Southerners it was time to end the union with their violent Northern neighbor.
Bernhard Thuersam, Chairman
North Carolina War Between the States Sesquicentennial Commission
"The Official Website of the North Carolina WBTS Sesquicentennial"
New England Ships Freighted With Sable Victims:
“When applied to slavery, the insights of evangelical religion effected a marked break from attitudes characteristic of the colonizationists. Thought advocates of [colonizing Africans away from America] often spoke of slavery using religious terminology, they saw the institution as basically a political, social or economic evil. [William Lloyd] Garrison and others who applied the logic of the revival to slavery saw it as sin.  The colonizationists found it practical to remove the evil slowly….By contrast, those who called for immediate emancipation were in large part calling for an immediate recognition of the sin of slavery, and immediate repentance.
The colonizationists had wanted to remove the Negro because he was dangerous. The immediate emancipationists thought that by removing the sinful shackles of slavery he would remove the danger and confront the Negro as a man.
In the Garrisonian view of slavery as sin, slave violence and race war played a major role. It was the just retribution for a sinful land. As surely as the repentant sinner would be saved, so the unrepentant sinner could only look forward to damnation. In the case of the individual slaveholder, for instance, damnation would come after death.
But Garrison’s view of the slavery question saw the nation as the sinner, and race war as its damnation if it refused to repent. “Slavery is strictly a national sin,” he stressed in his 1829 Independence Day address. “New-England money has been expended in buying human flesh; New-England ships have been freighted with sable victims; New-England men have assisted in forging the fetters of those who groan in bondage.”
When Garrison described his apocalyptic scene of blood and innocent victims, he made it clear that it was vengeance from Heaven” “The terrible judgments of an incensed God will complete the catastrophe of republican America.”
Time was running out on the nation in its bout with the sin of slavery. Emancipation had to be immediate in time because no one knew when the first clarion of an apocalyptic race war would sound throughout the land.  The sooner emancipation came, the less chance that American society would be consumed in violence.
It seemed to many of Garrison’s contemporaries that his excited warnings of impending slave revolt aimed at incitement rather than prevention of violence.  The Liberator’s columns played host to periodic warnings from Garrison and others of imminent slave revolt. [Garrison concluded in his] preface to an article on insurrection rumors from North Carolina with a stark message: “Such is slavery – a war of extermination on either side.”
(The Influence of Garrisonian Abolitionists’ Fears of Slave Violence on the Antislavery Argument, 1829-40, Robert H. Abzug, Journal of Negro History, Vol. LV, January 1970, pp. 16-19)