The U.S. were amongst the foot draggers on the issue of slavery.
You writing about Europe itself where slaves were as useless as they were in New England and the Middle Atlantic States or in the European colonies where they had value?
The slave trade is what was abolished, and it was largely political, Britain was for elimination as its colonies were filled up, and still didn't do crap to stop the Ottoman slave trade in the Balkans, because it needed to prop up the Ottomans to balance Russia. The Ottomans didn't renounce till the 1880's, Romania also kept it as a residue from Ottoman times for Gypsies.
only Brazil held onto the practice longer the U.S. did.
So did Puerto Rico and colonies not yet free in the new world
And doesn't morality exist in Africa and Asia where slavery existed long after 1865 and still exists? Look at Ghana and Ethiopia among other places,