Two events riled anti-slavery forces in America: 1) The Kansas-Nebraska Act, which negated the Compromise of 1820 and said that slavery could be wherever the State wanted it, rather than keeping it below a certain latitude (Mason-Dixon Line?). This caused violent men from both sides to fight in Kansas and Nebraska. The belief was that slavery, far from slowly dying out, would flourish in new Southern States (Cuba and Northern Mexico was seriously considered for annexation to the US)....for example, today Migrant workers work the orchards in florida and california....if the Kansas-Nebraska Act were present today, you might see slaves working those field today.
2)The publication of Uncle Tom's Cabin. This book stoked the abolitionist fires in the North, and a savage reaction in the South.
I honestly don't know how we could've avoided a Civil War. Southern Democrat slaveholders were too entrenched in their way of life, while northern Republican abolitionists were too angered by the idea of one man owning another.
As for "States Rights" and seceding because of economic issues, why didn't the Midwestern States secede as well (they were under the same restrictions Southern states were), and why was slavery forbidden to be outlawed in the Confederate Constitution?
“Two events riled anti-slavery forces in America:”
I believe you are overlooking a third, John Brown’s Raid in 1859.
John Brown bears an uncanny resemblance to today’s terrorists, a bearded fanatic who who believes that murdering people is his religious privilege. In his early murders at Pottawatomie creek he and his sons even used swords to slaughter their victims.
Brown’s terrorism was bankrolled by the 19th century equivalent of the Hollywood Left, the wealthy literary set of Boston that included the Howes and the Parkers. Otto Scott wrote a history of them in his book “The Secret Six”.
If I recall correctly the first man killed in Brown’s Harper’s Ferry Raid was a free black man who worked for the railroad. And one of the men they took hostage was Lewis Washington, a grand nephew of George.
In supporting Brown and turning him into a folk hero the North raised the ante to open violence. No longer was the slavery issue to be hammered out in the courts and Congress. The lesson for the South was that war had already been declared on them and they had better recognize it. A year or so later they did.