Slavery in America started in 1619, when a Dutch ship brought 20 African slaves ... in North America turned to African slaves as a cheaper, more plentiful labor ...
During formal discussion, mental notes could help you maintain your focus/attention for the point that given by another speaker so you could give your opinion or counter argument later.
This will give the impression that you're an attentive and a competent person.
Hernán Cortés, who was a coquistador and found the Aztec Empire and was viewed as a god because of when he arrived their god also was supposed to arrive.
