I don't know much about the story other than two families from different States... I know some of you are history buffs and could give me some history about it.... who would you rather be? A Hatfield or a McCoye?
Asa Harmon McCoy was murdered by the Hatfield clan on January 7, 1865 by a Hatfield. (He was murdered because he joined the Union army, and not the Confederate in the Civil War.)
Anything after that I don't really know, except through Wikipedia.