Because they had labor and skills Europeans didn’t. And because ndns were not accustomed to the diseases of the Europeans (ndns also could escape knowing the land). West Africans were already using forms of vaccinations for certain diseases. And their services as healers were…
Not only did Afrikan genius build this country, but Euro-Capitalist Financial institutions like Wachovia Bank got their start making money off the slave trade, not only profiting from their work, but their sale (taxes, auctioneering, ect) their travel on the middle passage (ship- building, trade, employment of sailors) and just about every other aspect of the colonial economy. This country was built on the backs of Afrikans, and its foundation still rests there.
Come on son. Harvard, Columbia (then Kings College) Yale all had ties in the trad. Brook Brothers made slave clothing. Virtually every industry in the us had ties to slavery. Whole family fortunes were made trading in slaves.