What was the main goal of European slave traders in Africa?

In particular, European traders wanted to trade for gold, which could be found in western Africa, and also to find a maritime route to "the Indies" (India), where they could trade for luxury goods such as spices without having to obtain these items from Middle Eastern Islamic traders.

Explanation:

European traders wanted to trade for gold, which could be found in western Africa, and also to find a maritime route to "the Indies" (India), where they could trade for luxury goods such as spices without having to obtain these items from Middle Eastern Islamic traders.

immigrants from northern and western europe continued coming as they had for three centuries, but in decreasing numbers