Sally, I don't look at being immoral as being a sinner. I prefer to think the two are different. Morality set by society and God's Law set by God.
Now if slavery was wrong, immoral, and a sin Why did General Robert E. Lee participate in it? The one man who, if thought slavery was all the above, would have stopped immediately. So no Sally, in my heart I don't think Slavery was a sin or immoral for the day.