I found this on a fascinating Civil War music site called Songs of the Union.

Hard Tack Come Again No More

Let us close our game of poker, take our tin cups in our hand
As we all stand by the cook's tent door
As dried monies of hard crackers are handed to each man.
O, hard tack, come again no more!

CHORUS: 'Tis the song, the sigh of the hungry:
"Hard tack, hard tack, come again no more."
Many days you have lingered upon our stomachs sore.
O, hard tack, come again no more!

'Tis a hungry, thirsty soldier who wears his life away
In torn clothes--his better days are o'er.
And he's sighing now for whiskey in a voice as dry as hay,
"O, hard tack, come again no more!"
--CHORUS

'Tis the wail that is heard in camp both night and day,
'Tis the murmur that's mingled with each snore.
'Tis the sighing of the soul for spring chickens far away,
"O, hard tack, come again no more!"
--CHORUS

But to all these cries and murmurs, there comes a sudden hush
As frail forms are fainting by the door,
For they feed us now on horse feed that the cooks call mush!
O, hard tack, come again once more!

FINAL CHORUS: 'Tis the dying wail of the starving:
"O, hard tack, hard tack, come again once more!"
You were old and very wormy, but we pass your failings o'er.
O, hard tack, come again once more!