I think in his book he acknowledges “The Steel Bonnets: The Story of the Anglo-Scottish Border Reivers.”
http://www.amazon.com/The-Steel-Bonnets-Anglo-Scottish-Reivers/dp/1632204568
Thanks, that’s a book I don’t know. I have read Fischer’s ‘Albion’s Seed’ which describes the four different groups from Great Britain that settled North America and essentially created the culture here, and “Born Fighting” seems to echo the section “Borderlands to Backcountry” about the Scots Irish. Funny how language and customs carried forward into my own life after who knows how many generations. My own family line is a blend of the south England cavaliers and the Scots Irish. Plus at least one New Orleans pirate.