What are the earliest texts that were against the atrocities that were occurring in Africa and the New World and how influential were they?

by Seven_Sayer

I specifically ask because I remember seeing this text on here years ago where someone mentioned a writing by some Spanish religious man in the 1500s who wrote about the atrocities in the Americas and why they were bad, but I can't remember what it was called.

jokerman38

A Short Account of the Destruction of the Indies(1552) by Bartolomé de las Casas comes to mind, although I am not sure if it is the earliest text.