The slave ship Mary left the African coast carrying enslaved Africans toward Grenada. About 135 people had been taken aboard.

Vessel: Mary; flag: Great Britain; rig: Brig; estimated standardized tonnage: 144. People recorded in connection with the voyage: Captain: Hodgson, Thomas; Investor: Hodgson, Thomas; Captain: Johnson, Robert; Investor: Johnson, Robert; Investor: Hodgson, Ellis L; Captain: Johnston, Thomas; Investor: Colley, James E. The voyage began at Liverpool on 12 March 1791. Principal recorded place where captives were acquired: Congo River (West Central Africa and St Helena). Principal recorded disembarkation place: Grenada, place unspecified. Estimated mortality during the crossing: 6.0%. Recorded outcome: Voyage completed as intended.