It is likely that such facts are omitted for the purposes of suppressing other realities that exist. For example, England entered into several treaties with Morocco in the 16th century prohibiting slavery long before the British implemented a public ban on the slave trade and before the United States enacted the Thirteenth Amendment.
Most discussions about Black History in America revolve around the expeditions taken after those that follow the adventures of the Barbary Company and the practices of English merchants in Andalusia preceding the formation of that company.
Questions about where the destination of slaves sold in Andalusia to English merchants is often not asked by African Americans because of the omissions of the English role in the Barbary aspect of the Atlantic Slave Trade which preceded English activity further south into West Africa.
“All the concerns of this essay begin in Andalusia. Slavery was a matter, raised by Shylock at his trial, in the Merchant of Venice narrative. This topic is of cultural relevance to early modern English audiences.”
“The bottom lines become clear in the earliest records of the English slave trade to which English American historiographers often omit from the discussion.”
“Records show that the first English slaveholders and traders of “enslaved Moors” were the English merchant’s resident in Andalusia in the last decades of the fifteenth and early decades of the sixteenth centuries, and further, that the English were the pioneers of the English slave trade with Morocco. … “