> I suspect slave holding was in existance longer and broader geographicaly than in the USA.

As a matter of fact it was. I don't see your point.

Slavemasters like to have slaves do the work. In the American South, the owners believed that they were doing the slaves a favor.

If they weren't slaves, they'd be non-Christian heathens in Africa at the mercy of lions and hyenas, living the lives of primitives.

Slavery was said to be better: it taught them Christian values (including the virtues of work) and it protected them from wild nature.

Did other slave-holding societies think that way? Undoubtedly some did: Brazil, for example.