Islam in Sub-Saharan Africa and Slavery

In his polemic against Islam, Richardson advances an interesting theory. He wonders why sub-Saharan Africa was not Islamized given that N. Africa and the Horn of Africa had been Islamized for many centuries by the time that the Christian missions and later the AIC's started winning millions upon millions of converts in the 19th and 20th Centuries.

His answer is that the Muslims were all slavers, given that the Quran clearly endorses slavery (and in fact has an entire chapter called The Slaves) and that the Prophet himself owned slaves, they only were able to Islamize the black Africans with whom they worked to enslave other Africans.

Had mullahs opposed slavery instead of condoning it, they could have ranged freely from Timbuktu almost to Cape Town, opening mosques and establishing Islamic school in the region. In short, they could have Islamized all of Africa, not just a fringe above and below the Sahara and on the coast of Zanzibar. (Richardson 203)

Secrets of the Koran by Don Richardson.