Final answer:
Portugal was the country that initially imported and enslaved thousands of people, with the Spanish, English, French, and Dutch following suit in the triangular trade.
Step-by-step explanation:
The country that imported and enslaved thousands of people to work on plantations and in gold and silver mines was Portugal. The Portuguese began transporting enslaved Africans to the Americas in large numbers, starting with the voyage in 1525 that brought two hundred Africans to Santo Domingo. Enslaved Africans were critical in the labor-intensive industries of sugar plantations and the extraction of precious metals. Despite Portuguese lead, other European nations like Spain, England, France, and the Dutch also engaged in transporting and using enslaved Africans for colonial economic enterprises.
Learn more about Transatlantic Slave Trade