there is an index for Adairs in Virginia, Chronicles of the Scotch-Irish Settlement in Virginia.
some which may be connected are -
Mar 25 1746. John Carmichael vs John Wilson, debt on bond by defendant Mary Anne CAMPBELL, witnessed by Wm. ADAIR, signed by Morgan Campbell. (perhaps Morgan and Mary Campbell were parents of Mary Campbell who m. Donald / O'Donald / O'Donnel then Adair ?)
p.338, Mar 30 1772. Wm. Campbell, security for Mary Donald (administrator of husband's estate, Michael O'Donald). Mary remarried John Adair.
Feb. 10 1771. Jas. McClure vs. John Adair and his wife Mary (late Mary O'Donnell). .................... Did some Adairs emigrate with McClure or Gaston families : William Gaston, bc1690, Cloughwater, Co Antrim, Ireland son of John Gaston & Olivet Lemon.
John Gaston, b.1703, Cloughwater, Co Antrim, N.Ireland, d.1782 m. Esther Waugh
Mary Gaston, bc 1712 Ireland, dc 1802 at Upper Fishing Creek, Chester Co, SC, m. James McCLURE
Robert Gaston, bc1720 Co Antrim, N.Ireland, d.prior 1787 Lancaster Co, SC, m. Margaret Logan