The McCreary (incl. McCreery, McCrary & more spellings) DNA Project needs a lot more samples. A mouth-swab sample from any McCreary/McCreery/McCrary-surnamed male thought to be biologically descended from a McCreary (& variant spellings) guy of early America would be great. With enough samples, meaningful groupings by common ancestry become possible, and this hopefully will also help to correct some errors in family tree formulations.Higher resolution yDNA tests (e.g. 67 STR markers) help to put the number of generations to a Most Recent Common Ancestor within a researchable time frame, but even a 37 markers test is better than nothing.
I descend from Hugh McCreary (d. 1808, Fayette County Pennsylvania). My McCreary Blog: http://mccrearyline.blogspot.com/http://mccrearyline.blogspot.com/I am not affiliated with the McCreary DNA Project, but am a fan of their work.