That’s a really heartwarming ending to the story of the Hatfield-McCoy feud, but a complete myth, nonetheless.
True, there had been a Romeo-a-Juliet-style romance between two of the young-uns, but their romance lasted only long enough to start a pregnancy before the fickle young Hatfield boy took up with his girlfriend’s cousin and wisely moved out of the feuding zone before the fireworks really started.
Nothing really ended the feud, exactly; it just sort of trickled out as the families dwindled and the law intervened.