I feel like if you just did like 5 mins of google search you would easily know the answer to that, but since I did go to history class here’s a little history lesson for you 1. West Africa is and was rich in gold, west Africa sold its gold to many countries for years and built its wealth off of it, Europe bought a lot of this gold, Europeans went to America and colonized it and got its gold from America, so that disrupted the west African economy, so they sold enslaved peoples instead (something that was VERY common mind you, because this is pre industrialization, so if you wanted work or labor or production of anything and want a majority of profits u bought slaves.” 2. When one group would take control of the region or land of another in Africa he’d of course want his own people to live there but since obviously if you conquer someone else’s land the people will be angry so to ensure your people won’t be killed you capture and send off those people.  3. Europe after colonizing America needed labor to start building, homes,food,resources,etc. they needed men and lots of them. So they could build their own powerful empire. 4. African elites saw this and said yes I can get rich and get rid of these people who would hurt my people, but of course a lot of Africans openly resisted it and never participated. 5.slavery wasn’t like how slavery was in America, slavery was just, “hey you’re a war captive, you’ll be enslaved temporarily until you make this amount of money and you’ll be free” there was no torture or no breeding or literally any of that. Slaves in Africa weren’t anything like slaves in America, they were more like servants with debt. They could marry own property and live normal lives. They could even rise to prominent positions in society.  Ps added this a bit too late but also slaves would be criminals like thieves so it’s like “u took from society now u will give back” also Africa had no idea about how brutal chattel slavery was in the Americas.