Just like you don't get to decide what offends me, you need to study your history a bit better. The war was, indeed about economics, and states' rights. The Emancipation Proclamation didn't even abolish slavery in one Confederate and four Union states: Tennessee, Maryland, Delaware, Kentucky and West Virginia.
... To say the war was about economics, not slavery is like saying our dogs are about fetching, not retrieving. The entire economy of the south relied on slavery, and they faced economic collapse if slavery was abolished! The two issues were so closely intertwined, they were inseparable.