The slave ship Mercúrio arrived with enslaved Africans in Brazil. About 420 people had been taken aboard and approximately 384 arrived.

Vessel: Mercúrio; flag: Portugal / Brazil; rig: Bergantim. People recorded in connection with the voyage: Investor: Mesquita, Francisco Pereira de; Captain: Pereira, Anacleto de Jesus. The voyage began at Rio de Janeiro on 18 June 1821. Principal recorded place where captives were acquired: Benguela (West Central Africa and St Helena). Principal recorded disembarkation place: Rio de Janeiro. Recorded duration of the captives' Atlantic crossing: 41 days. Estimated mortality during the crossing: 9.0%. Recorded outcome: Voyage completed as intended.