It is necessary at the beginning to consider two events that some historians, and many feud chroniclers consider part of the events leading to the conflict between the two families.
The timeline I created above reflects the key events from the folklore of the feud. Some of them are historical fact muddled by the tales of the feud and retelling of the story in popular media. One of the most recent was the History channel sponsored three-part series produced and starring Kevin Costner. It is beautifully filmed, superbly acted, and actually gets some of the facts right. You can check out the trailer at the link below.
January 7, 1865 - Asa Harmon McCoy is killed by Confederate rebels, part of the Logan Wildcats.
The death of Asa Harmon McCoy at the hands of Confederate rebels is often used as a starting point for conflict between the Hatfields and McCoys. There are several problems with this point, one being that the majority of the Hatfield and McCoy family members that fought in the Civil War fought for the Confederacy. Asa was an outlier from both families by his support of the Union.
The feud lore claims that Anderson Hatfield as a leader of the rebel group known as the Logan Wildcats chased down the cowardly Union soldier Asa Harmon McCoy and finding him hiding in a cave, killed him.
The record however tells a different story. There was a group known as the Logan Wildcats: It was a militia group formed in Logan County prior to the war. Once the Civil War broke out, it became Company D of the 36th Infantry, and remained in service in the regular Confederate Army until it was mustered out three days after Lee’s surrender. Anderson Hatfield never appeared on its roster and there are no records that this unit ever came within a hundred miles of the Tug River Valley.
What the record does show is that Asa Harmon McCoy, far from being a coward, had received a severe chest wound and been captured by Confederate forces. After a time as a prisoner of war, he was released to return home and heal from his wounds. He immediately rejoined the Union war effort, Breaking a leg soon after, he recuperated and was back in action again less than two months later. Finally discharged from military service on Christmas Eve of 1864 he returned home but re-upped and was killed by rebels as he attempted to return to his regiment. Far from being a coward!
Marking this event as the beginning of hostilities between the Hatfields and McCoys is problematic since there is no record of violence from either family towards the other until 1882 - seventeen years later!