Why by 1861 was the compromise between the North and South no longer possible?

The
election of Abraham Lincoln in 1860 was really the last straw for the Southern states. His
election, along with the rise to power of the Republican Party, spelled doom in the minds of
Southerners. Although Lincoln would probably not have pressed for an end to slavery immediately
had there been no secession or civil war (his later Emancipation Proclamation was really as a
result of the war), Southerners believed that Republicans would eventually abolish slavery or,
at the very least, allow no more slave states to be admitted into the Union. This would have
greatly decreased the...