I have a possible genealogy breakthrough in the Buchanan line.
Our ancestor Andrew Buchanan's father may be a John Buchanan estimated to be born about 1750, from Fintona, Tyrone, and likely a child or grandchild of William Buchanan and Margaret Creery of Fintona. This William Buchanan may be the former Laird of Blairvockie or his son. William Buchanan, Laird of Blairvockie sold his estate in Stirlingshire, Scotland to his cousin John Buchanan and moved to Fintona in County Tyrone, Ireland.
This may be our connection to the chiefly line of Clan Buchanan. What has led me to this point is:
1. The YDNA tests that identified our family as a typical chiefly line of Clan Buchanan. We have found close YDNA matches with the Buchanan families of Cooel and Kirlish in the Drumquin area, of County Tyrone, but no perfect match.
2. Darlene's autosomal DNA test that finds Samuel David Keys as a possible 2-4th cousin. David Keys is a descendant of Samuel Buchanan and Samuel Buchanan's wife Matilda Buchanan, so he could have autosomal DNA from two Buchanan families. Samuel and Matilda lived in Cooel, but have no known living male Buchanan descendants so a YDNA test is not possible.
3. The Tyrone Constitution article that mentions Samuel and Matilda's daughter Mary, being named after her grandmother Mary Caldwell.
4. The Buchanan Book (Alexander Buchanan of Montreal, descended from William Buchanan and Margaret Creery, stating that William Buchanan descended from the Laird of Blairvockie who sold his estate to a cousin and moved to Fintona, Omagh, County Tyrone, Ireland..
5. Genealogist Auchmar's Buchanan history, which gives information on the Lairds of Blairvockie/Blairvocky and their connection to the chiefly line of Clan Buchanan. [A Historical and Genealogical Essay Upon the Family and Surname of Buchanan]
IN MORE DETAIL
From Darlene's autosomal DNA test, and the timeline, Andrew Buchanan our ancestor could be a brother or other close family member) to Samuel or Matilda Buchanan. Samuel's father is said to be John Buchanan of Fintona born about 1750-1760, who might be a son of William Buchanan and Margaret Creevy of Fintona who married in 1733 and had a son John born in Fintona about 1740-1750 From The Buchanan Book, this William appears to be the former Laird of Blairvockie or his son.
So there are lots of maybe's. But it seems like something worth following up on. I am asking for help from a cousin who has researched multiple Buchanan lines.
3. Tyrone Constitution Friday 20 April 1906
"Last week we stated that Dr. J M Caldwell of Blackbury [sic Blackberry], South Carolina, was desirous of tracing his ancestors in Ireland. As an indication of the importance of the “Tyrone Constitution” as a news conveying and advertising medium, we received a letter in the beginning of the week containing some information regarding the matter. Mrs. John Buchanan, Hill House, Cavandoragh, Magheracriggan, Castlederg, County Tyrone, is a relative of William Caldwell, who left Cavandoragh,(Megaracriggan being the post town)in the parish of Ardstraw, and on the Duke of Abercorn’s estate. A sister of William Caldwell was married to John Buchanan of Cooel, and their son, Samuel, to Matilda Buchanan of Drumclamph. Mary, their daughter was named after her grandmother, Mary Caldwell, from Cavandoragh, whose brother William Caldwell, went to America, She was married to John Buchanan of Cavandoragh."
4. Family of Dr. George Buchanan of Fintona, Co. Tyrone. Pages 315-317
"Beaver Buchanan, of Fintona, born in 1710, was descended from William Buchanan, last of Blairvockie, who settled in Ireland. According to Mr. Thomas Hardinge Buchanan, of Dublin, who has made extensive researches as to the family of Buchanan in Tyrone, Beaver Buchanan was the son of William Buchanan of Fintona, who died in 1764. This William Buchanan married, in 1733, Margaret Creery, and had four sons, John, who had a son William; Andrew, William and Beaver, and three daughters, Anne, wife of Andrew Anthony; Margaret and Alice. This William Buchanan appears to have had two brothers, Eccles Buchanan of Fintona, who died in 1762, and John Buchanan of Mullamenagh, living in 1764. Eccles Buchanan, of Fintona, was married three times: first, in 1724, to Mary Pitkem; secondly, in 1748, to Margaret Johnston; and thirdly to Elizabeth . He had four sons, Thomas, John, Robert and George, and a daughter, Margaret. ..."
[I also see Beaver Buchanan listed elsewhere as born in 1840, which is more consistent with the marriage date for his parents, but perhaps inconsistent with the birth dates for his children. Maybe William had a marriage previous to his marriage to Margaret Creery?]
This seems like a possible solution to a long-lasting genealogical puzzle in Ireland, a country with few records prior to 1864. DNA tests can fill in some of the gaps.