The slave ship Mercury arrived with enslaved Africans in Uruguay. About 331 people had been taken aboard and approximately 272 arrived.

Vessel: Mercury; flag: Great Britain; rig: Ship; estimated standardized tonnage: 241. People recorded in connection with the voyage: Investor: Parr, James; Investor: Rackham, John; Captain: Hume, Robert; Investor: Hume, Robert. The voyage began at Liverpool on 18 June 1803. Principal recorded place where captives were acquired: Africa, port unspecified (Other Africa). Principal recorded disembarkation place: Montevideo. Recorded outcome: Captured by pirates or privateers - after embarkation of enslaved people.