My son Harry Grier recently tested with Family Tree DNA. He is classified I1 within the Greer/Grier Viking Group. Our Georgia Grier branch descends from Robert Isaac Grier b. 20 Feb 1735 in Northern Ireland, possibly Armagh or Antrim. Robert was from a Quaker family. He changed his name from Greer to Grier after he arrived in America. He arrived in Pennsylvania in 1749. He returned to Ireland to marry Catherine Elizabeth McMurry Burns, a widow, of a different faith, probably Presbyterian. Robert and Catherine returned to PA and purchased land in Lower Chanceford, York, PA. They and 6 sons and daughters were in Georgia by 1773 where they remained. I can find no connection with the other Greer/Grier colonial families. If you can help we will appreciate it.
Also who else is collecting Grier/Greer/ Grierson Y-DNA reports? Harry is already participating in the Greer/Grier Project, McGregor Project and Ulster History Project,and Scottish Clans Project through FTDNA. We would be happy to provide report results to any group conducting Grier and related surname projects.