Memorial Day, in the United States, was begun just after the Civil War as a day of remembrance for those who died in that conflict. It now honors all U.S. military who died in action.
Here's a translation by Arthur Waley of a Chinese poem from about 124 B.C.
Fighting South of the Castle
They fought south of the castle,
They died north of the wall.
They died in the moors and were not buried.
Their flesh was the food of crows.
"Tell the crows we are not afraid;
Crows, how can our bodies escape you?"
The waters flowed deep
And the rushes in the pool were dark.
The riders fought and were slain:
Their horses wander neighing.
By the bridge there was a house.
Was it south, was it north?
The harvest was never gathered.
How can we give you your offerings?
You served your Prince faithfully,
Though all in vain.
I think of you, faithful soldiers,
Your service shall not be forgotten.
For in the morning you went out to battle
And at night you did not return.
Two thousand years later -- not much has changed.