The correct answer to this open question is the following.
You forgot to attach the statement for reference. Without that statement, we do not know what you are talking about.
However, after doing some intensive research, we can comment on the following.
One important social response in the Americas in the period 1492-1607 is that black African slaves became a critical element in substituting Native American Indians in colonial American society.
As Native American Indians never assume a role as slaves, European colonists decided to buy slaves from Africa, in what was known as the Salve Trade. These slaves were transported in inhuman conditions in ships that traveled for months until they reach the American shores. Slaves traveled in overcrowded spaces where diseases could spread easily.