It's impossible to definitively predict what would have happened had the outcome of the U.S. Civil War been different. The Confederate States of America was formed on the principle of preserving slavery, and its constitution explicitly protected the institution. Therefore, it's likely that slavery would have persisted in the southern states had the Confederates achieved their goal of independence. The abolition movement had gained significant momentum at the time, but whether it would have succeeded in eradicating slavery without the Union’s victory remain speculative.