Anne Stephenson b.c1742 married James Adair Sr.,of Chester Co,S.C. found in DAR. records.
Anne and James Adair had a son James Adair,Jr.married ___ issue: Edward Adair Fowler Adair. William Stevenson of the Turkey Creek Stephensons mentioned "Cousin Fowler Adair" in his memiors Other children of Anne and James Adair married Dale and Kennedy.
This is Adair information is from a Genealogical Sketch of the Family of David Stephenson of the Turkey Creek Section of York County,S.C. In his old age David Stephenson went to Chester Co,S.C. to live with his daughter Anne Adair
David Stephenson who settled on Turkey Creek in York County,S.C. is believed to be the David Stephenson who shows up on church records in Old Augusta County,VA.,now Rockbridge. My John Stephenson settled on nearby Bullocks Creek in York County,S.C. He is believed to be from old Augusta County,Va.
Wlliam Stevenson settled in Iredell Co,N.C. The book on William claims that he had a brother,John,who settled in Blackstock which is in Chester County,S.C.
In 1772,Four Stephensons sailed with the Rev.William Martin from County Antrium,Ireland directly to South Carolina.Several of these Stephensons settled in Chester Co,S.C.These Stephensons used the spelling of "Stinson" All these Stephenson,Stevensons,Stinsons,no matter what the spelling,had in common that they came to America from County Antrim,Ireland and were Presbyterians. The Stephensons originated in Scotland. By the early 1700's there were John,William,James,and Robert Stephenson living in County Antrim,Ireland.I believe that the early Stephenson's who came to America were related to one of the above brothers living in County Antrim,Ireland.
Sorry,I don't know about the Adair emigration. You might be interested in typing in a search engine,Rev. William Martin and his Five Ships" to see if the Adair surname is mentioned among the passengers.