Just when you think you know the boundaries for the poisonous legacy of slavery, the field gets bigger.
"Black in Latin America," a four-part series hosted by Dr. Henry Louis Gates, visits six Latin American countries and finds each in its own way still struggling to resolve that legacy.
Nor, Gates stresses, are these small isolated pockets of slavery descendants.
Of the estimated 11 million Africans who survived the notorious "Middle Passage," only about 450,000 ended up in the United States. The other 10.55 million went to Brazil, Haiti, Cuba, Mexico and the rest of the Americas. Anywhere plantation owners or farmers needed free labor, there was a market for slaves.
So take the lingering toxicity of slavery in the U.S., multiply that more than 20 times, spread it over many nations, and Gates finds that being of black ancestry in Latin America can present challenges both common to the hemisphere and unique to countries or communities.
Just on the island of Hispaniola, which Gates visits in Tuesday night's opening episode, slavery left far different imprints on the two nations that uncomfortably share the land, Haiti and the Dominican Republic.
In Haiti, African slaves overthrew their colonial rulers in the 19th century, a bold act that in turn impacted many other slave-holding countries.
The Dominican Republic kept slavery longer, leading to a differently tiered society and contributing to that country's distrust and, in some cases, disdain for Haiti.
In Cuba, which Gates visits next week, slave owners virtually imprisoned their slaves, trying to preclude the sort of congregating or conversation that could lead to a similar revolt.
If slaves were an invaluable part of the U.S. economy, necessary to make the economics of cotton production work in the South, they were equally or more essential to the sugar growers of Cuba.
The Cuban segment deals with the question of who is black. For years, high status in that country meant being "white," yet the island has so much mixed blood that the distinctions became almost impossible to quantify.
What Gates clearly finds, though, is that even after Cuba's revolutionary leader, Fidel Castro, officially abolished racial discrimination, some Cubans still carry the residual sense that black folks aren't as smart or developed as "whites."
So the discussion, and the struggle, goes on. This may surprise some U.S. residents, who assume that black-and-white issues disappear at our southern borders and everyone below that point is some compatible shade of "brown."
On the contrary, in many ways Latin American and Caribbean countries deal with the same struggle that people have in the U.S. - just as frustrating, just as complex and just as deeply rooted in the poisonous legacy.