Answer:
A united nation with slavery abolished
Why?
We can easily take out,two nations, one with slavery and one without, and, a united nation with slavery only in the South. This is because after the civil war there was no slavery as it abolished. We can eliminate,a united nation with a new system of government, because our government did not change, only the laws. This being, a united nation with slavery abolished, is the answer because our nation was one united again and slavery was abolished.