Cool. How about the French view? I wonder what the Germans thought? Or how about looking at 3 million people freed from slavery because of the EP in the two years after the EP was issued or the 100,000 of those freed slaves who served in the United States Army?
The Union had slaves before the Confederacy.
The Union kept slaves after those in the Confederacy were freed.
If the Confederacy had freed their slaves, the Union would still have been against secession.
Explain how these facts fit with your contention that the war/secession was about slavery.