[laotzu]

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.

[Non-Sequitur]

If the Confederacy had freed their slaves, the Union would still have been against secession.

If the south had freed their slaves, they would have had no reason to secede in the first place.