The Civil Wars - Barton Hollow Lyrics Meaning

I think the song is about sin and not being able to be forgiven for it by themselves for the crime they committed.

From the line, "or that unmarked hundred grand" it suggests unmarked money that was either made or stolen or possibly a payment for a different crime. Also the previous line, "did that full moon force my hand?" makes reference to the myth that a full moon can make people act crazy or differently then normal.

The song has strong religious overtones as well that go with sin/forgiveness. Such parts of 'forgive me father' and 'preacher man' and the bible prayer Now I Lay Me Down to Sleep that they changed around some. They also talk about 'bathing in the river' which is an old tradition, usually only used still in the south, which is being baptizied and saved from previous sins committed.

Finally they talk about how they can't be forgiven with referencing that 'being a dead man is the least of my fears' (obviously from possible persecution if they had went back to barton hollow), also
'no preacher man can save my soul', 'no good washing in the river' and 'walking and running and running for miles'.

The only part I'm not sure of is the reference to 'Alabama clay'. I think it means blood on his hands as Alabama clay is known for being really red, so it could be that.