Final answer:
The Netherlands took over as the dominant force in the early transatlantic slave trade from the Spanish and Portuguese in the early seventeenth century, but were soon challenged by the English, who eventually became the primary carriers of African slaves.
Step-by-step explanation:
The nation that ousted the Spanish and Portuguese from their status as dominant forces in the early slave trade with Africans in the early seventeenth century was the Netherlands. The Dutch wrested control of the transatlantic slave trade from the Portuguese in the 1630s, although by the 1640s they faced increasing competition from French and British traders. The English, in particular, became the primary carriers of Africans to the New World after 1651, maintaining this position until the end of the trade in the early nineteenth century.