I know some of the Hatfields did marry Mc Coys. I have some in the data-base. My Hatfields bn. in Tn. or Virginia as the earlier ones. We are out of the line of George Hatfield.
I have found some of the Hatfields did marry Mc Coys. My Hatfields went to Pike County from Tn. in abt. 1870. They did a name change at that time however. Back to HAtfield at lest by 1900. when my Grandmother marr. James W. Hatfield.
With these circumstances, I still have not found some of my Grandfathers brothers and sisters. So some could have gone in W. V. not sure. Some of the down lines to us, may or may not know of their Hatfield line. I know some married under the other name. Complicated. I have been working for 3 years. Wwith the internet you can cover a lot territory. Also have been in all areas I know of to visit.