Why did the Spanish Empire rely on the native population to mine silver?

s the president shall be commander in chief of the army and navy of the united states, and of the militia of the several states, when called into the actual service of the united states; he may require the opinion, in writing, of the principal officer in each of the executive departments. sooo yeahhh

explanation:

i think u are supposed to write a long-essay answers to the long-essay questions

the correct answer is a: slaves from other colonies ran away to georgia.