How did human trafficking become an integral element therein?

In what ways was the European exploration and conquest of large parts of the New World after 1490 driven by the intersecting motivations of religion and politics at home in Europe? How did these varying motivations help drive the Columbian Exchange? What was the latter? How did human trafficking become an integral element therein? (This question does not violate what I said about the exams coverage. This material was assigned reading from Hunt and comes specifically from the period of the Reformation and the Catholic response.)