When tour guide Pedro Andres arrived at the site historians call the most important physical evidence of the arrival of enslaved Africans to the Americas, the scene he found was familiar. The Valongo Wharf was empty.

Addressing a family of Paraguayan tourists, Andres described its historical significance. At the height of the transatlantic slave trade, nearly 1 million enslaved Africans arrived on its cobblestones, more than landed anywhere else, and twice as many as were trafficked to all of the United States. UNESCO has called the wharf, discovered in 2011 during an urban renovation project, a “unique and exceptional” place that “carries enormous historical as well as spiritual importance to African Americans.”

But Andres, who brings tourists to the wharf of his own volition and not because it’s recommended by his tour agency, saw little indication of that remarkable history. There are no memorials. Only a single sign above a large puddle far removed from the street. The wharf has been unearthed but is still ignored. Even people who live nearby, whose ancestry leads back to this point, don’t know of its existence.

“Sad,” said Andres, 26. “Sad that slavery ever happened, but also sad that its history is being neglected.”

How that history is honored at the site, and who gets to make those decisions, are questions at the core of another struggle over race and memory in the country that brought the most enslaved Africans into the Americas. The dispute, which pits federal prosecutors and historians against the right-wing presidency of Jair Bolsonaro, echoes a racial reckoning in Brazil that in recent years has taken on some of the country’s darkest moments and most enduring contradictions.

Brazil historically has demurred on questions of race, preferring instead to understand itself through the lens of class. Its intellectual elite have long described the country as a “racial democracy” forged by intermarriage and unencumbered by the racism plaguing other countries. But it also imported nearly 5 million enslaved Africans — an estimated 40 percent of the transatlantic slave trade — and in 1888 was the last country in the Western Hemisphere to abolish slavery.