This is a very personal story. It is that of the many white Americans today grappling with their own ancestral identity, entwined in the horrors of the African slave trade. It is not really the story of the African American. But that's OK because everyone has feelings, everyone has the right to process their own past, 'tepid self indulgent' (quote from previous reviewer) whites included.
However my lower rating comes not out of criticism for the film's credibility, just that I am not a fan of these 'personal journey' type documentaries. I was hoping it was more informative and less egocentric, as it focused more on their reactions to places and events rather than a rigorous break-down of the North's involvement in the legal and illegal slave trade. More focus on slave plantations in Cuba would have been appreciated also. But again, that wasn't the purpose of this documentary.
On a side note: a particularly poignant moment in the film was near the end, where each of the family members discloses their educational history; 8/9 attended (or parents attended? Was unclear) Ivy League schools. That's not a coincidence. Money and privilege run down through the generations, as does poverty and disenfranchisement. These are symptoms of the past, which is why healing and understanding and ongoing support is so crucial for the historically subjugated.