Southern born and bred here but to say slavery had nothing to do with the war is like saying our involvement in the Middle East has nothing to do with oil.
We must remember that FIVE SLAVE STATES remained with the Union. Missouri, Kentucky, Maryland, Delaware, and the break away WEST Virginia. That means while the UNION was fighting to free the slaves in the South, the slaves in the North were still under the STARS AND STRIPES, and the LASH.
Some of the UNION officers in that war still had slaves as they led troops in the field.
Delaware refused to release their slaves till the 13th Amendment was ratified, EIGHT MONTHS after the war ended.