And that would not have made our cause any less just, nor the British one more just.
The military defeat of the Confederacy does not mean they were wrong, they were wrong because secession is wrong.
Secession is not ipso facto wrong, and it is neither allowed nor prohibited by the U.S. Constitution. As to the Union cause, there was a godd reason why Lincoln adopted a policy against slavery. "World Opinion,"--that is the powers of Europe, until then saw it simply as a power struggle. Shortly before Lincoln announed the Emancipation Proclamation, the liberal British statesman Gladstone was in favor of recognizing Southern Independence. After it, public opinion in Britain went to the side of the Union.