What was the civil war rhetoric like to make the north and south convincingly view each other as enemies?

by ArmedShadowfox

I’m trying to understand how at no point the mass populations stopped to think, “how can we go to battle with our own countrymen, regardless of our political differences..”

I know it goes deeper than this but am unsure of the specifics

Georgy_K_Zhukov

This answer might interest you, especially the followups quoting from letter and diary excerpts.