And vice versa, the people who pushed for abolition (in the US anyway) did not do it for economic reasons either. It was a deeply moral mission initiated by, basically, religious fundamentalists. Then followed on by more mainstream liberals, still for ethical reasons, and then followed on by the masses once war broke out over it.
A similar pattern in the UK, bar the war.
There was use of military force to suppress the slave trade but not actual war https://en.wikipedia.org/wiki/West_Africa_Squadron