After the Arrival of Portuguese and other European traders. How did the African slave trade change?

The slavery in Africa was nothing weird, as most of the tribes had slaves, which were usually people that they have captured in battles that they won with other tribes.

When the Portuguese and later the other European colonial powers came to Africa and started purchasing the slaves from the local tribes, the slave trade changed. The local tribes were either paid, or the slaves were exchanged for weapons. That led to a fear in the rival tribes, so they started capturing more and more people so that they can get weapons too. That led to much more local battles in order to get slaves, which of course benefited the Europeans as they needed a lot of labo force for their plantations in the New World.

Explanation:

your answer is 1930's

explanation

this is just around the time the great depression was starting and putting the us ecnomy into ecnomic failure causing the goverment to take a much larger rule to try and pieace it back together