The song appears in W. W. Newell, 1883 (1903, later eds.), "Games and Songs of American Children," No. 15.

"A girl sits in the ring and turns her head gravely as a messenger advances, while the rest sing to a pleasing air-" (music given)

Green gravel, green gravel, the grass is so green,
And all the free [fair*] masons (maidens) are ashamed (arrayed?)to be seen;
O Mary, O Mary, your true love is dead,
The king sends you a letter to turn back your head.
[*fair] my suggestion.

Newell believed that the song might be a fragment of a ballad, and compares it with a French round.

Later, as no. 172, he gives a rhyme from Toronto, Canada:
Green Gravel

Green gravel, green gravel,
The grass grows so green,
The fairest of ladies is fit to be seen.

Dear ---, dear ---,
Your true love is dead;
He sent you a letter
To turn back your head.

"Turning the head is a sign of sorrow; in some British versions the game is continued by another in which the lost lover appears, and the dancers, who have all turned about, are one by one made to face the ring; as Miss Burne suggests, I think that "Green Gravel" was meant to receive such continuation." "In this case the lover has gone to war, and the letter announcing his death..."
"I do not now regard the game as the reduction of a ballad."

There seems to have been a schism in meaning- 1. a lover gone to war, and 2. the death and burial of a maiden (or maidens).