“But you don’t hate slavery?”
Yes, I do. But, you do realize, I assume, that slavery — evil that it was and still is — was legal in the United States up until 1865. That being said, I would have vigorously opposed another country invading us to abolish slavery.
The south made the mistake of attacking Sumter, lost their slavery as a result. No one invaded to get rid of slavery, it was a fringe benefit of the war.