Although some slaves were brought DIRECTLY to the American mainland, most of them were first brought from Africa to the West Indies to islands like Puerto Rico, Jamaica, Haiti/Dominican Republic, and Cuba.....to be "broken".
There was a PROCESS in turning proud civilized cultured Africans into "slaves".
A process that often involved generations.
Making them eat certain types of food, depriving them of their native languages, and forcing them to engage in weird sexual activities.
There is a book about it that was out years ago called "64 Years To Make A Negro".