This is Hidden Brain. I'm Shankar Vedant.

It was a cold day in Appalachia on January 7, 1865.

A union soldier named Asa McCoy was on his way home,

wounded from fighting in the Civil War.

As he neared his cabin in Kentucky,

Asa was given a message,

Don't return home, or you will be killed.

A local group of Confederate militia,

known as the Logan Wildcats, planned to kill Asa.

The Wildcats were led by a member of the Hatfields,

a family living in West Virginia who had strong ties to the Confederate Army.

Asa hid out in a cave near Peter Creek, Kentucky.

But it was no use.

He was eventually tracked down and shot dead.

The incident is said to have sparked a famous feud between the Hatfields and the McCoys.

It lasted decades.

In 1873, a McCoy family member, perhaps still seething from Asa's death, accused Floyd Hatfield of stealing his pig.

A trial followed, and Floyd Hatfield was acquitted.

A few years later, one of the trial witnesses was killed by two McCoys.

In 1882, on Election Day in Kentucky, some McCoy brothers drunkenly fought and killed Ellison Hatfield,

stabbing him multiple times in the back.

In retaliation, the Hatfields killed all three McCoy brothers.

...