It was really really cheap. They used to use indentured servants which were white or black. Indentured servants would work for their master for like 8 years or so, and after such time they would be free, along with theoretically land.
Slaves were much more efficient, since they were hard working, 100% free, and would work for you until they died.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.