This question seems built on the assumption that not only did Europeans actually go and gather up slave, but also the assumption no African worked with them. Countries along the coast of Africa worked with Europeans in the slave trade, and the slave trade in Africa existed before Europeans arrived. Europeans rarely went on land and gathered the slaves themselves, they engaged in trade for them with the African powers on shore who would gathered the slaves and bring them to trade with the Europeans for various goods. Taking slaves in Africa was a significant thing, especially in conflicts between groups/tribes/countries.

The person that asked this question did realize the above, correct? Otherwise, this is a loaded question.

Not at all.

There was a triangle trade route from west Africa for slaves to the Caribbean for sugar to Europe to process sugar to rum and then back down to africa with rum and money to pay for slaves. The slaves were internally generated and sold to the europeans, Africa had a rather amazing slave trade network.

Slave trade: a root of contemporary African Crisis Tunde Obadina

There's also a really good book i read on the Rum trade i read ages ago called A Bottle Of Rum or something but i can't find a link for the damn thing.