Let me make this clear. There existed a vigorous abolitionist movement in certain parts of the North. But upon closer examination, the movement was miniscule. It was so small that most politicians, including Lincoln, did not risk their political fates by actively associating themselves with abolitionists. No abolitionist was ever elected to a major office in any Northern state.
It should be apparent to any serious student of American history that in the 19th century, today’s modern conceptions of basic human rights did not exist. Most Americans in both the North and South were opposed to slavery but slavery abolition was not high on their priority list. Most white Southerners did not own slaves. Many Northerners viewed free slaves as job competition. Most white Northerners were unconcerned with the welfare of slaves and often mistreated even the free blacks who lived amongst them. The economic, social and political systems of the North often systematically separated blacks from whites. Black Codes often existed in Northern states before and after the war. Lincoln’s home state, Illinois, amended its state constitution to prohibit the emigration of blacks into Illinois. There was little to no popular support in the North for the legal abolition of slavery. In fact, in 1864, long into the war, an abolition amendment to the US Constitution was offered in Congress and, even without the presence of the Southern states and an ongoing bloody war, it failed.
As important as the abolitionist movement was the role of religion in teaching that slavery was morally wrong. The dramatic increase in the church role helped to make abolition a political issue. Also, the political philosophy of the antebellum period derived from the Enlightenment and promoted natural law and the natural rights of man as defined by such men as John Locke and Thomas Jefferson who saw the inherent conflict between slavery and natural rights.
Many influential Southerners opposed slavery. People such as Governor Letcher of Virginia and Robert E. Lee were slavery opponents but favored gradual emancipation, believing that most slaves were not equipped for immediate freedom. Virginia came very close to abolishing slavery on her own until the Nat Turner Rebellion made people away from immediate emancipation. The threat of slave insurrection was a constant fear among white Southerners. Not only was Nat Turner willing to kill slave owners, he was willing to kill any whites including women and children. Books such as Uncle Tom’s Cabin had a profound impact on Northern thought. The cruel, simplistic, cartoon like picture it depicted both of Southerners and slavery fixed in people’s minds a lurid impression of the plight of slaves to the average Northerner. Such writings tended to produce a reflex action in the South, causing some to angrily defend Southern institutions such as slavery. John Brown’s infamous raid on Harpers Ferry augmented the fear of slave insurrection in the South and caused further sectional strife. Brown was financed by wealthy northern abolitionists who viewed Brown’s murderous plans as collateral damage. But the raid left many Southerners wondering about their place in the Union.
The formation of the Republican Party as a Northern regional party whose sole unifying plank was the abolition of slavery coalesced politically various liberal, Whig, and dissident Democrats under a broad tent. The split of the Democratic Party into three wings guaranteed Republican victory. The Republican electoral victory in 1860 without any Southern support directly led to the secession of South Carolina. To most Southerners, the administration of a high tax, pro-Northern business, anti-slave Republican Party led by corporate railroad lawyer Abraham Lincoln was too bitter a pill to swallow and the years of constant sectional strife finally had taken its toll. The South would exercise its constitutional rights and leave the Union.
I would argue that the writings and actions of abolitionists certainly helped drive a sectional wedge and increase political tensions in America. Most Northerners seemed more concerned with slavery extension than with abolishing slavery. Lincoln himself actively supported the Corwin constitutional amendment which would forever allow slavery in states where it legally existed. Lincoln was more interested in preserving the Union than in abolishing slavery. Even up to his bitter end on April 14, 1865, he supported re-colonization of blacks to Africa and South America. Paradoxically, many Northerners were often as much concerned with keeping blacks in a subordinate position as they were in liberating them.