The real issue is we have a large group of black people so ashamed to be from Africa, and ashamed of the historical slavery fact, that they make up laughably ahistorical origin stories to make themselves feel better. This is bad, and frankly pretty sad.
We have ledgers, documents, ship records, journals, etc documenting the transmission of African slaves from Africa to North America. We have similar documents for Columbus and similar "explorers" who discovered North American "Indian" civilizations. It's certainly a fact that there was some level of trade or a relationship between ancient North Americans and Africans but there is no evidence there were millions of black people in America, who were enslaved. To the contrary we have evidence of Indians being enslaved initially before mass influxes of Africans...from Africa...on ships that are documented.
This goes back to the Kyrie thing and the way disinformation and stupidity run rampant. Stop believing what you want to hear because you're ashamed of one part of your heritage.