Arguments that slavery was undesirable for the nation had long existed, and early in U. history were made even by some prominent Southerners.After 1840, abolitionists denounced slavery as not only a social evil but a moral wrong.Overall, the Northern population was growing much more quickly than the Southern population, which made it increasingly difficult for the South to continue to influence the national government.By the time the 1860 election occurred, the heavily agricultural southern states as a group had fewer Electoral College votes than the rapidly industrializing northern states.His victory triggered declarations of secession by seven slave states of the Deep South, whose riverfront or coastal economies were all based on cotton cultivated using slave labor.
Amid the emergence of increasingly virulent and hostile sectional ideologies in national politics, the collapse of the old Second Party System in the 1850s hampered politicians' efforts to reach yet another compromise.
Most of the debate is about the first question, as to why some southern states decided to secede.
Abraham Lincoln won the 1860 presidential election without being on the ballot in ten Southern states.
A small antislavery movement, led by the Quakers, had some impact in the 1780's and by the late 1780's all of the states except for Georgia had placed some restrictions on their participation in slave trafficking.
Still, no serious national political movement against slavery developed, largely due to the overriding concern over achieving national unity.