Then the retort is that the Africans must have been some weak people who couldn't fight of a handful of scurvy-ravaged white teenagers and 20 year-olds with nets and muskets, all in a land with malaria and wild animals they've never seen before.
You really have no understanding of how the typical African slave trade worked. Captives were taken either during tribal warfare or by small expeditions seeking captives to trade. These captives at some point traded to Muslim traders who had defacto control over the inland trading routes. Major routes led to Egypt, the Arabian peninsula, Madagascar (forwarding to Asia) and to the West African Gold Coast serving the New world. Whole nations and empires were built on the slave trade. Most of the benefactors were black, the controllers Islamic. The preceeding does contain some generalizations due to the variety and extensive news of the trade.
The African tribe from which Obama derived was a Muslim African tribe which captured and sold black slaves to the slave merchants from Europe. That is Obama’s heritage.