In the 19th century, Rio de Janeiro emerged as the largest slaving port in the Americas. Every year, ships, mainly from Brazil and Portugal, poured thousands of enslaved Africans in that port. But what happened to them after they disembarked? This paper examines a database of passports and other sources compiled by the Brazilian Institute of Applied Economic Research to address that question. It also discusses the challenges and methods of adjusting the database to an ongoing project focused on the intracontinental slave trade in the Americas from the 16th to the 19th centuries. The paper shows that, although Rio de Janeiro was the final destination for many slaves disembarked there, a significant proportion of them was reexported into the interprovincial traffic, to regions as distant as Minas Gerais, São Paulo, and Rio Grande do Sul. In the 19th century, Rio de Janeiro emerged as the largest slave-trading port of the Atlantic. Every year, ships sailing from almost all regions of Africa, south of the Sahara, poured tens of thousands of enslaved Africans there. Those suspected of carrying diseases were quarantined at a lazaret across the Guanabara Bay until they passed the health inspection and were cleared to proceed to their final destination. All ships deemed free from diseases were allowed to sail directly to the port and disembark their human cargo. Once on land, slaves were taken to the Valongo Wharf-possibly the largest slave market in history-cleaned, and put for sale to the highest bidder. Thousands upon thousands crowded the streets and alleys of Valongo wondering what would happen to them. The wharf has recently entered UNESCO's List of World Heritage Sites, a move that emphasizes Rio's role in the transatlantic trade, but it begs a question that has often passed unanswered: what happened to these individuals