Who were the Hatfields and the McCoys?

They were two extended families that lived along the border between West Virginia and Kentucky along the Great Sandy river. They were involved in guerrilla warfare during the Civil War and shortly after the end of the war the feud broke out.
There was bad blood between them and the feud between them lasted for many years. It is generally believed that the catalyst that caused it was determining the ownership of a pig.
ok it was not over a pig hatfields killed a brother of a mccoy becaused he wasnt raciest or whatever and he avenged his brother and then they started killin off each other and in the middle of it randolf mccoy had pigs and a hatfield stole some so he shot him and that's how that started-Britany McCoy