Conversation so far:
What was John W. Campbell's take on slavery?
John W. Campbell pointed out that slavery in the American South had provided the blacks brought there with a higher standard of living than they had in Africa.
Did John W. Campbell become an activist for Slavery?
John W. Campbell wrote, It's my bet that the South would have been integrated by 1910.

Question: Why did he believe that?
Self-contained rewrite: Why did John W. Campbell believe that the South could have been integrated by 1910?