Hatfield-McCoy Feud
[ hat-feeld-muh-koi ]
/ ˈhætˌfild məˈkɔɪ /
noun U.S. History.
a blood feud between two mountain clans on the West Virginia–Kentucky border, the Hatfields of West Virginia and the McCoys of Kentucky, that grew out of their being on opposite sides during the Civil War and was especially violent during 1880–90.