How did the European traders capture slaves in west Africa?

In most cases, European traders did not capture slaves. West African nation states controlled the regions from which most slaves were abducted; thus Europeans had very limited access to people beyond the coast. As in Europe, African states were sometimes engaged in war, which produced captives, some of whom were kept in a form of indigenous African servitude. After the arrival of Europeans, tribal chieftains began to trade such captives of war, along with other goods. As the American plantation system grew into a highly lucrative enterprise, so did the demand for chattel slaves (human property). Gradually, Europeans became aggressive participants in the abduction of slaves and played a dominant role in organizing slave-raiding parties whose business it was to the capture other Africans in exchange for European goods--weapons, liquor, beads, cloth, etc. European traders then transported victims to the Americas as "merchandise," making a profit on human misery.