Why were African slaves imported to work on encomiendas in Latin America?

Las presiones ejercidas por sectores de la Iglesia y la disminución de la población indígena, determinaron que la corona permitiese el ingreso de negros africanos para que sustituyeran a la mano de obra aborigen.  

Explanation:

Por lo tanto, la encomienda no implicaba la propiedad sobre los nativos; era una concesión no heredable

the tariff was created to protect industry in the northern part of the united states. industries in the north were being driven out of business by imported goods that were priced at a low rate. the goal was to protect these industries   by taxing the goods.