
Trying to build tree for all Callahan surnames back to their beginning.
Resources:
https://www.facebook.com/groups/1835241990064285/?ref=share
https://www.familytreedna.com/groups/callahan/about/results
https://www.theirishrose.com/name-histories-coat-of-arms/callahan-n...
https://www.ancestry.com/name-origin?surname=callahan&key=Uhttp...