Anyone with the smallest knowledge of history could contradict that assertion.
Visit any islamic country and see... but beware you may never return with your head or you may be put into slavery yourself. You will not be picking cotton.
In some ways, yes, most notably in its color line and "one drop rule," which, oddly enough, black leaders of today have revived.
Spiritually and mentally it was deadening and oppressive, arguably the worst in history.
Physically the American South was perhaps the most positive slave society ever for the slaves. At any rate, it was just about the only slave society in history where the slaves not only reproduced themselves, they had a population explosion.
Ancient Greek and Roman slavery, and the slave societies of the Caribbean and Brazil were dependent on constant imports just to maintain the numbers of slaves, but slaves in America grew every in numbers every bit as fast as their white overlords. People just don't do that when they are horribly oppressed.