The most beautiful war poem ever written was by Walt Whitman.
It's called "Reconciliation."
He wrote it at the end of the Civil War.
"Word over all, beautiful as the sky.
Beautiful that war and all its deeds of carnage
must in time be utterly lost, that the hands of the sisters
Death and Night incessantly, softly wash again,
and ever again, this soiled world.
For my enemy is dead.
A man divine as myself is dead.
I look where he lies, white-faced
and still in the coffin.
I draw near, bend down, and touch lightly with my lips
the white face in the coffin."