How did slavery help start the civil war?

This is largely due to the fact that many people feel this is more justifiable. The real reason for the Civil War was State's rights. Slavery was the main catalyst. Never forget that Lincoln himself stated that if he could keep the southern states from seceding by allowing the institution of slavery to continue, he would. Lincoln's sole reason for going to war was to preserve the Union. There are many aspects of the U.S. economy and society in the time leading up to the Civil War that actually LED to the war itself. It wasn't just slavery. There isn't one definite answer to why the war started. The reason they say slavery started the war is probably because it was one of the many aspects beginning to be controled by federal government at the time. The Southern states felt that their state rights were being impeded upon by the government. One of these rights was their "right" to own slaves. Hope that answers this a bit. Slavery was AN ISSUE, but not THE CAUSE. Slavery would have eventually been abolished for economic reasons without the war. There were some in the North who truly saw slavery as an evil that should be abolished, but the majority was not so vehemently opposed to it. Only a very small percentage in the South owned more than one or two slaves and therefore had an economic interest in maintaining the status quo. Actually, only 5% owned even one slave. What can we compare this to in today