On 22 September 1826 John Heathcock married Margaret (Peggy) Harrison, the widow of James Harrison, whom she had married in 1824. John Hathcock was Margaret's third husband. Born Margaret Shackelford, her first husband was Major John Cook.

Margaret Shackelford Hathcock is last found in the 1860 census of Madison Co NC, age 70 (16 Jun 1860). She reported her state of birth as North Carolina. John (age 85) and Margaret were living next door to the family of John Heathcock Jr. and his children Dodson (male age 21), Hulda (female age 18), Caladonia (female age 16) and Nelson (male age 14).

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From Shackelford Clan Magazine:68

Richard and Mary Ann Roberts-Shackelford had another daughter named in his will as Margaret, wife of John Cook. And we have very little information of the Cook family, therefore would be grateful for anything additional.

John Cook was known as Major John Cook, and records of Madison County, Alabama, show that he died July 8, 1822. And from the deeds and settlement of his estate we find that John and Margaret Shackelford-Cook had the following children:

Emily----------(married Calvin Shackelford (cousins))
Margaret-------(married James Harrison ??)
Isaac----------(married Mary Ann ??)
Clayton--------(married Telitha or Tabitha)
Mary Ann-------(married ??)
John B.---------(married ??)
Elizabeth-------(married Alfred Hathcock)

Our records show that John and Margaret Cook had a daughter Margaret that married James Harrison, but this is questionable, as she does not show up in the division of John's estate.

Margaret Shackelford-Cook married for her second husband -- John Hathcock. We have no record of any children being born to that union.