"Black people would still be slaves if your process had been followed."
Not so. You may want to note that I also said that people should work to change laws they disagree with. I guarantee I'd have been working to overthrow slavery, had I been alive during that time.
Many people did do that work, and slavery was ended.
The abolition of slavery was not going to be accomplished through the application of laws. It took a war. It always takes a war to defeat evil. Another war is coming.
And the only good thing about it is the judges don't have an army.