Answer:
Ancient China 2100 – 221 BC
Explanation:
The transatlantic slave trade began during the 15th century when Portugal, and subsequently other European kingdoms, were finally able to expand overseas and reach Africa. The Portuguese first began to kidnap people from the west coast of Africa and to take those they enslaved back to Europe.
You are going to have to search it up online to get your answer
Because they could be turned into slave states, giving more power to the slaveowners in the south. Also, expansion policy and the dram of Manifest Destiny played a part in desiring that land.
