According to the essay, "Black digs up his past", the remote racial origins of African-Americans are important because these origins offer annotations of achievements made by them.
These achievements are not what African Americans and the world have made themselves understood.
On the one hand, African-Americans with greater profitability are not separated or differentiated from the rest, but are part of their culture and history.
And on the other hand, African-Americans need to see that they also contributed to their own liberation.