Answer:
pre-Columbian slave trade.
Upon colonizing the New World, the Europeans ushered in fundamental changes in the Americas' political, social, economic, and cultural makeup.
you may know, many of these changes had consequences that crossed oceans to impact the lives and livelihoods of people worldwide....
an example would be
that this was enslavement of humans from Africa. many people today say that this was an African holocaust.
Slavery goes way back in history, it's a vast or broad subject.