Sarah Hinckley Mitchell Abercromby (?-1787) married Moses Mitchell on 25 November 1760 as his second wife, at St. Philip's Parish, Charleston, South Carolina. The register does not include the usual designation of "spinster" or "widow" for the bride.

Moses Mitchell (?-1775) had previously married Mrs. Mary Marriner, whose maiden name was Harris, in the late fall of 1735, but they had no children. Mary Harris had married Edward Marriner at St. Philip's in Charleston on 12 April 1724. Mary Harris Marriner Mitchell died about 1758.

Moses and Sarah Hinckley Mitchell had five children in Charleston: Sarah Mitchell (1761-1819) who was deaf and never married; Moses Mitchell II (1763-1780) who was both deaf and mute and died of a leg wound inflicted by cannon shot as he watched some of the Revolutionary War battles during the siege of Charleston; William Mitchell (1766-1767); John Hinckley Mitchell (1767-1832) who was bequeathed his uncle William Hinckley's (?-1780) book case and library of books in 1780 and afterwards, in 1790, married his cousin, William Hinckley's only surviving child, Ann Hinckley McGillivray Russell, as her third husband; and William Henry Mitchell (1769-1787).

Among Moses Mitchell's children, only John Hinckley Mitchell had descendants.

William Hinckley, by 1737, owned a lot in Georgetown, South Carolina two blocks from James Abercromby's lot there and mentioned his sister, Ann Abercromby, in his 1780 will. In 1779 William Hinckley "of Charleston, merchant," gave this Georgetown lot # 160 for "natural love and affection" to his spinster nieces, Eleanor and Elizabeth Ball, daughters of Joseph Ball of Charleston, a trader.

At his death in 1775, Sarah's husband, Moses Mitchell, was a wealthy man. John [Joseph] Abercromby along with George Monk and Stewart Nicolls witnessed Moses Mitchell’s will on 22 October 1775 after Mitchell became seriously ill. Moses Mitchell died a few days later, on 26 October 1775. And on 4 January 1777 Mitchell’s widow, Sarah, married John Joseph Abercromby at St. Philip's Parish, Charleston.

A year after their marriage, on 15 January 1778, a devastating fire broke out on the north end of Union Street in Charleston and destroyed all Union Street and the south side of Queen Street. Not only was Moses Mitchell's home destroyed, but also nearly all the buildings owned by his estate. As a consequence of losing her home, Sarah Abercromby, wife of John Abercromby, in early May 1778, purchased for 8,000 pounds South Carolina money a residence at 2 Queen Street, one of few houses that had not burned.

Sarah Hinckley Mitchell Abercromby died at Charleston on 7 January 1787.