You have already lost the debate. By assuming the war was about slavery, you have closed off other perspectives.
This narrow interpretation of the War fails to account for political issues, economic factors, regional/cultural differences, taxation, constitutional rights, etc. Yours is an abolitionist view. The tendancy to simply the cause of the War is an injustice.
See #105 above. South Carolina explicitly states the reason for their decision to secede was because of slavery.
How would you respond to the pro-choice argument that banning abortion isn't about protecting infants, but about continued oppression of woman.
To me it seems the same sophistry as saying the war wasn't about slavery.