But need them it most certainly did. And not just to win a war. Not just to save a Union. But to save a Nation's soul. To save a Nation's humanity.
Oppression always claims two victims.
The oppressed and the oppressor. You can not brutalize, you can not put down another human being and not irrevocably corrupt your own soul. Oppression can make you rich, but its price is your humanity. A society that brutalizes the African, can not help but oppress its women. A society that brutalizes the African, can not help but poison the environment.