How did colonization of the Americas contribute to the development of the slave trade? {from Scientific Revolution and the Age of Exploration}

The colonization of the Americas gave the mother countries new land to exploit. They extracted natural resources, such as silver from Potosi and created plantations where they grew cash crops like sugar and tobacco. However, to run these operations, they needed labor. At first, with acts like the Spanish encomiendas, they forced the natives to work. Soon though, the natives died from European diseases like smallpox that were brought over. They fixed this labor shortage with African slaves, who were stronger and had more immunities.