You are leaving out the immense opposition to slavery for the evil that it was, by trying to make it economic issue .
The vast majority of Americans saw the evil of owning humans and were strongly opposed to it.
People in small Ohio towns didn’t elect Lincoln so they could buy cheap plantation land .
But good and evil are not legal topics. Socialism is a great evil, the most evil thing in the history of mankind, but it’s law in many countries.
You may hate drugs with a fervency, because its’ evil, but it’s legal to use.
I’m just pointing out that good and evil are not legal concepts.