“Southern Succession and the Civil War were about slavery.”
If your response is, “duh!” then just ignore this.
But if you believe otherwise, if you think hundreds of thousands of people were fighting and dying for the principle of preserving the union or abstract concepts of state’s rights, if you think Robert Lee was an abolitionist, if you think the Civil War was more about economics than morality or race, if you think slavery was just a footnote to the Civil War (and that’s what I was taught by one of my not-so-good history teachers in high-school), then read this excellent post from Ta-Nahisi Coates.