I know that native americans and south americans were used as well, to a lesser extent but it seems like you'd risk less people dying in transport. Is there some significance to the Africas slave trade?
Do you mean in the northern colonies or in what's now Latin America?
The short answer is numbers and religion. "Latinos" would then have been Iberian settlers and the growing mestizo population of Spanish America and Brazil, themselves a colonial elite often employing unfree labour.
The Iberian colonies faced the same labour shortage as the north as the native population sank under the impact of epidemics. The northern colonies for their part lacked the numbers (with only about a quarter of a million c.1700) to seize captives from the south on a large scale.
Additionally, the Church had long forbidden enslavement of fellow Christians (except as convicts), ruling out even converted or peaceful native Americans. Convict labour was disliked as unreliable and unconducive to moral order, and northern colonies moved to end transportation of criminals.
That left purchase as the most acceptable and feasible way for a wealthy emerging landed elite to work its estates at low cost. And Africa had a slave trade lately joined by European intermediaries. So began the trade that would ultimately swallow twelve million.