The only info I have on this family group came from Morton's "Hist of Highland County".Harmon Hiner is named as the husband of Jemima McCoy.The info on the children of John McCoy and Sarah Oliver from this book is:
ROBERT NAME:Named in father's will. BIRTH:1761 date from "Hist of Highland County", Morton, pg.319. NOTE:Possibly the same as married Margaret Matron 29 Nov 1791 by Rev. Benj. Irwin as listed in "Augusta Co., VA Marriages".
ELIZABETH NAME:Named in father's will. BIRTH:1763 date from "Hist of Highland County", Morton, pg.319. MARR:John McClure per Morton.
OLIVER NAME:Named in father's will. BIRTH:1765 date from "Hist of Highland County", Morton, pg.319. MARR:Margaret Johnson per Morton.
JANE NAME:Named in father's will. MARR:William Gamble per Morton.
WILLIAM NAME:Named in father's will. BIRTH:20 Sep 1768 date from "Hist of Highland County", Morton, pg.319. NOTE:Per Morton "General William McCoy became a merchant at Franklin and was a large landholder in both Pendleton and Highland.He purchased the Peninger and the Ulrich Conrad selections at and below the mouth of the Thorn, and gave much of his care and attention to this well-stocked farm.His prominence as a public man in his own county caused him to be elected to Congress in 1811, and to be returned for eleven consecutive terms.When he went to Washington the national capital was a far remove from the fine city it has recently become.The straggling town of only 9000 people was threaded by unpaved and muddy streets. The long period of 22 years of service was not only a compliment to the ability of General McCoy, but it was also a compliment to his county, Pendleton being the most remote in his district and the least populous and wealthy....In Congress he was a man of influence.He was a trusted friend of President Jackson, and for many years he held the important post of Chairman of the Committee on Ways and Means.He was also a member of the Constitutional Convention of 1829.His Congressional career was brought to a close by a stroke of parlysis.In person he was tall and spare with a commanding figure. His wife was a kinswoman to Pres. William H. Harrison". MARR:Elizabeth Harrison.
JOHN NAME:Named in father's will. BIRTH:Abt 1770. MARR:Catherine Williams per "Hist of Highland County", Morton, pg.319.
BENJAMIN NAME:named as a child of John McCoy whose will was probated in Pendleton Co., VA in 1796.Listed as father of Henry McCoy in Highland County Vital Statistics Death Records.(Highland County, Virginia created from Pendleton County, Virginia. BIRTH:Abt 1772. MARR:Margaret Mary Jones per "Hist of Highland Co.", Morton, pg 319.NOTE:records of Kent Bodkin, referencing Morton's "Hist of Pendleton Co." names Benjamin's wife as Margaret Sims.This needs further research.Benjamin's son, Henry's death record lists his parents as "Benjamin and Mary McCoy".
SARAH NAME:Named in father's will. MARR:Jacob Hiner per Morton.
JOSEPH NAME:Named in father's will. MARR:Margaret Bodkin per Morton.
JEMIMA NAME:Named in father's will. MARR:Harmon Hiner per Morton.