Stephen Vincent Benet - 1936

All night they marched, the infantrymen under pack,
But the hands gripping the rifles were naked bone
And the hollow pits of the eyes stared, vacant and black,
When the moonlight shone.

The gas mask lay like a blot on the empty chest,
The slanting helmets were spattered with rust and mold,
But they burrowed the hill for the machine-gun nest
As they had of old.

And the guns rolled, and the tanks, but there was no sound,
Never the gasp or rustle of living men
Where the skeletons strung their wire on disputed ground ...
I knew them, then.

'It's eighteen years,' I cried. 'You must come no more.'
'We know your names. We know that you are the dead.
Must you march forever from France and the last, blind war?'

'Fool! From the next!'
they said.

Stephen Vincent Benet

http://www.poemhunter.com/poem/1936/