My interest in the Craighead-Heart family comes from the possibility that my ancestor, Jane Dunlap (b. c. 1775), wife of James Cousar (d. by 1813) of Gills Creek in Lancaster District, SC, was a daughter of Samuel Dunlap (b. c. 1757) and Mary Craighead, daughter of Rev. Alexander Craighead and Jane Brown, granddaughter of Rev. Thomas Craighead and Margaret Wallace, and great-granddaughter of Rev. Robert Craighead and Agnes Heart.
A common error that appears all over the internet is that Mary Craighead married Samuel Dunlap (1715-1791), but that Samuel was the father of her husband.
After Mary Craighead's death, Samuel Dunlap (Jr.) seems to have married Lydia Anderson, daughter of Cornelius Anderson. He and several of his children moved to Tennessee. He is last recorded (as far as I know) in Mar 1836 in Haywood County, but had lived in Humphreys county before that. He had several children, but it isn't always clear which of his wives was the mother of which child, nor is it always clear which grandchild was born from which child.
If Jane Dunlap who m. James Cousar really was his daughter (which is not proven), then chronology would suggest her mother was Mary Craighead and that she was the eldest child. I also think his son Robert Dunlap (d. by 1836 in Humphreys County, leaving a widow Elizabeth) might have been by Mary Craighead. I am of the opinion that Anderson Dunlap (m. Mary), William Dunlap (m. Phoebe Hall), Allen Leroy Dunlap (m. Mary), Sarah Dunlap (m. Rev. James Forrest), and Samuel Dunlap III (m. first Jane Crawford, then Nancy Riggs) were Lydia Anderson's children, but I could be wrong about one or more of them.
James Cousar (d. by 1813) and his wife, Jane Dunlap, had four sons:
Robert Cousar (c. 1789-bef. 18 Dec 1811) married his cousin Nancy Ann Dunlap, daughter of Thomas Dunlap and Catherine Foster, and had one son, Robert H. Cousar (1806-1892). Nancy married secondly, _____ Crockett, and she and Robert H. Cousar moved to Fleming County, KY, where Robert married one Julia Ann and left issue.
Samuel Cousar (c. 1790-1854) married Margaret McElmoyle and had James E. Cousar (c. 1821-1882), John J. M. Cousar (b. c. 1824), and possibly Aminta Cousar (c. 1833-1885). James E. Cousar married Mary Jane Hemby. Aminta married John David Caskey (c. 1828-1899).
Archibald B. Cousar (b. 1791-1792, d. 1830-1840 in Tennessee) married one Elizabeth (b. c. 1797) who, after his death, married _____ Maddox. Their children seem to have included Samuel Franklin Cousar (b. c. 1820), Richard E. Cousar (b. c. 1824) who married one Lorinda (b. c. 1829), Archibald Dunlap Cousar (b. c. 1827) who married one Nancy Jane (b. c. 1837), Martha Cousar (b. c. 1832), Charles Cousar (b. c. 1835), and a son, dead by 1850, whose wife was Louisa (c. 1826-1850). There was perhaps a son named Matthew Cousar, as well. Mrs. Elizabeth Maddox and at least some of her Cousar children moved to Mississippi County, AR.
James D. Cousar, Jr. (bef. 1794-bef. 10 Dec 1825), married Bethia Hood (1788-1856), who later married Andrew Gamble. Her Cousar children were Ann Louisa Cousar (1811-1882) m. Hugh Montgomery (1805-1845); James H. Cousar (1812-1854) m. his cousin Nancy Cousar Kirk; Jane Narcissa Cousar (1814-1881) m1. (in 1838) William Blackstock, m2. James Hood; Allen H. Cousar (1816-1845); Richard Henry Cousar (1818-1903) m1. his cousin Susannah L. Dunlap, m2. Margaret Matilda Craig; and probably William K. Cousar (1820-1845).
I am descended from Richard Henry Cousar by his second wife Margaret Matilda Craig.
Robert Dunlap (b. 1776-1780, d. bef. 1836), who might have been a son of Mary Craighead, married Elizabeth H. I believe (but could be wrong in one or more of these cases) that his children included:
Samuel A. Dunlap (b. 1811-1820, d. bef. Oct 1840) m. Nancy Rushing
Rev. Robert Richard Dunlap (1818-1885) m1. Pamela Hubbard Parker, m2. Mary Louisa Williams
Salina Dunlap (b. c. 1826) m. David Rushing
James Madison Dunlap (1828-1886) m. Amanda Leona Parker
Jonathan H. Dunlap (or John H. Dunlap, b. c. 1834)