Even if one accepts the notion that the Civil War was primarily over slavery...and it's arguable...it's not a matter of "The South practiced slavery and the North didn't."
The overwhelming majority of the original colonies practiced slavery. At the time the Constitution was ratified, I believe only Pennsylvania had never been a slave state. A big hunk of the shipping trade through Massachussetts was conducted by slavers, and there was a slave auction block in Boston harbor. John Adams was himself a slave owner (albeit briefly; he was given a young woman house slave as a gift, and owned her only long enough to make out the manumission papers). Sojourner Truth was born a slave in the Hudson River valley of New York.
So if the North has any moral ground to stand on with regard to chattel slavery of blacks, it is only this: They got religion on it before the South did.
Very true on the North and South both being complicit in the slave trade.I grew up in California but lived in the South for three years.
Attitudes were pretty much the same.