Question

Why did the Spanish Empire establish a system of unfree labor in the Americas?

Answer 1

Mainly to produce wealth for the Spanish Empire by exploiting their conquests. The Native Americans that were conquered were the first to be turned into a ready supply of slaves and a huge number were forced into mines and in working the land in order to make the colonies prosper.

When sickness from new diseases brought to the New World by the Europeans annihilated the native population, slaves from Africa were brought in to make up the difference.