Answer
So that their slaves are less likely to escape.
Step-by-step explanation:
The Spanish adopted domestic slaves to ensure high production that would allow them to pay for their expedition and settlement. During the first decades of their colonization, thousands of native people died from the harsh, severe labor of the plantations or gold mines. Finally, the enslavement of native peoples was forbidden, but that just unlocked the door to the entrance and subjugation of black slaves.