Were native Americans in both North and South America ever used as slaves? If so, why did the use of Africans become so popular? Wouldn't it have been easier to have enslave people that were already there instead of shipping Africans across the ocean? Also were natives seen as being higher up in the social hierarchy compared to African slaves or were they seen in the same regard to Europeans?
The natives were used as slave labor, but due to disease pathogens their bodies weren't used to, they quickly died. Successive waves of diseases wiped out up to 90% of the native population in certain areas.
The natives never had the chance to be saved, so legally they couldn't be forcibly enslaved (according to the Pope). Africans were often met with Islam before they encountered Christianity, so they were often considered OK to enslave. As such, importing a ton of Africans to the new world as forced labor was acceptable to the Catholic Church in ways enslaving the natives wouldn't be.
Natives were actually used as slaves, especially under the encomienda system of Spanish America. While Spaniards were technically entrusted with the care of the indigenous populations they were, in reality, forced into hard labour. Through a combination of atrotious living standards and disease, these populations were quickly wiped out in many regions and so Africans were brought in to replace them. By the 19th century Native slavery was outlawed mostly through the efforts of Dominican and Franciscan missionaries.
Cortes' own chaplain wrote that "the Conquest of the Indians began when the conquest of the Moors had ended, in order that Spaniards may always war against the infidels." In essence, no, Natives were not initially viewed in any sort of favourable light. At least not by the Spanish colonial leaders. Some missionaries on the other hand did view them as souls that could be saved. Bartolome de las Casas, for instance, spent much of his life fighting against institutions of Native enslavement and abuse.
Bishop Zumarraga (1468-1548), of New Spain, was influenced by Erasmian humanism. He believed that whether black or white, all people are "brother with the lord." He spent much of his time building schools, hospitals, and attempting to extend the protection of the law to native populations. Whereas the Spanish conquistadors tended to believe that some men were only fit to be slaves.
One historian, Donald Kurtz, put forth the theory that it was Zumarraga who created the myth of the Virgin of Guadalupe (Mexico's most famous Marian image) particularly to prove to Spanish colonials that Natives were persons and that God offered them his protection. Mary is said to have appeared before a Native man, Juan Diego, and had the appearance of a Native woman, which she imprinted on the back of his tilma (peasant cloak). As seen here.
