Not slavery, not civil war.
If slavery never existed there never would have been an American Civil War.
According to (ducksters.com). Many northern states banned slavery and were concerned that the United States would ban slavery because it was the cause of the war. The government decided that freedom is the ideal in American history.
According to (libertyclassroom.com). Slavery is certainly a factor in the civil war, and it is wrong to say that slavery is not the main reason for the secession of the state's far north and south.
If slavery were not present there never could have been the American Civil War, but not the only one of wars are never simple and not the causes. Many other factors that contributed to the war is essential to the understanding of America's past.