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.
Why did John W. Campbell believe that the South could have been integrated by 1910?
Rapidly increasing mechanization after 1850 would have soon rendered slavery obsolete anyhow.“

Question: Did people believe him?
Self-contained rewrite: Did people believe John W. Campbell's claims about slavery?