This thread has a lot of references to the surname Casey. I am the FTDNA administrator for the Casey YDNA project and one of the co-admins for the R-L226 Haplogroup project (the second largest Irish haplogroup with 540 testers at 67 markers). My Casey line and two others (who do not share a common Casey ancestor) are also R-L226. Around 25 % of the the 75 Casey YDNA testers are R-L226 with the remaining members spread across many other haplogroups that can not share a common Casey ancestor (well over 1,000 years old).
Where we know the Irish county of origin, 80 % of the R-L226 testers are from the following Irish counties: Tipperrary, Clare, Cork, Kerry and Limerick. 10 % are from other Irish counties and the last 10 % are from many other countries (mainly England). We know that this haplogroup is of Dal gCais in origin as the surnames align very well with the Dal gCais and Sir Conor O'Brien (title holder of the O'Brien surname) has tested R-L226 positive.
My particular Casey line first appears in United States in the early 1750s in western South Carolina. Speculation was that the South Carolina line was connected to another Casey line in Virginia - but to date, several of the Virginia Casey lines have been YDNA tested (where Ancestry.com states they are connected to the South Carolina line). Unfortunately, YDNA continues to disprove these connections due to non-matching YDNA (no common ancestor in the last 4,000 years). The only European in this cluster that matches this Casey cluster is a Kersey who traces his line back to Oxford, England in the early 1600s. We suspect that this person was originally a Casey (due to sharing a very unique YSTR signature and very recent YSNP branch) but changed his surname to the English surname Kersey to hide his Irish ancestry.
We have 75 YDNA testers for Casey men, unfortunately we do not have a single Casey tester that currently resides in Ireland today. We do know that South Carolina Caseys were very prolific and by 1800, there were around 50 adult Casey males in South Carolina). This branch of the Caseys probably represent 25 % of all Caseys in the world today. Recent Social Security records indicate around 50,000 with the surname of Casey (this includes women). Many children are not included unless they have entered the work force to pay Social Security taxes. My father and I published a "Casey Family History" book in 1980 and I have greatly expanded this publication to include several of the major South Carolina lines that I believed to be related.
If you have a male Casey ancestor that are well proven back to the 1870s and still reside in Ireland today in the five Munster, Ireland counties listed above, I will sponsor (pay for) a 37 marker test at FTDNA ($139 value). The only other requirement is that if you turn out to connected to one of the major Casey lines in the United States, is that you would allow additional extensive testing to determine your exact relationship. It would also be preferred if the tester also upgrade to 67 markers if you match one of the major Casey lines (cost of $99). If you match the South Carolina cluster of Caseys, our project would probably sponsor a Big Y test ($575) or a Whole Genome Sequencing test ($775). Feel free to email me, mail me or call me at contact method of your choice:
http://www.rcasey.net/DNA/Casey/Contact.htmlHere is page that shows our Casey testers at 67 markers for the South Carolina cluster:
http://www.rcasey.net/DNA/R_L226/Haplotrees/L226_Home.pdf#Page=27
