There are folk songs in the Irish and American traditions about women posing as men to go to war, like this Irish one, called "Jack-a-Roe" (Spellings of this name vary)
There was a wealthy merchant, in London he did dwell
He had a Beautiful daughter, the truth to you we'll tell
Oh the truth to you we'll tell
She had sweethearts a plenty, and men of high degree
But none but Jack the sailor, her true love ever be
Oh her true love ever be
Jackie's gone a sailing, with trouble on his mind
He's left his native country and his darling girl behind
Oh his darling girl behind
She went down to a tailor shop and dressed in man's array
She climbed on board a vessel to convey herself away
Oh convey herself away
Before you get on board sir, your name we'd like to know
She smiled on her countenance, they called me Jack-A-Roe
Oh they called me Jack-A-Roe
I see your waist is slender, your fingers they are small
Your cheeks too red and rosy to face the cannonball
Oh to face the cannonball
I know my waist's to slender, my fingers they are small
but it would not make me tremble to see ten thousand fall
Oh to see ten thousand fall
The war soon being over she went and looked around
among the dead and wounded her darling boy she found
Oh her darling boy she found
She picked him up on in her arms and carried him to the town
she sent for a physician to quickly heal his wounds
Oh to quickly heal his wounds
This couple they got married so well they did agree
This couple they got married so why not you and me?
Oh why not you and me?
Oh why not you and me?
Or this American one, called "Cruel War"
The cruel war is raging, johnny has to fight
I want to be with him from morning to night.
I want to be with him, it grieves my heart so,
Wont you let me go with you?
No, my love, no.
Tomorrow is sunday, monday is the day
That your captain will call you and you must obey.
Your captain will call you it grieves my heart so,
Wont you let me go with you?
No, my love, no.
Ill tie back my hair, mens clothing Ill put on,
Ill pass as your comrade, as we march along.
Ill pass as your comrade, no one will ever know.
Wont you let me go with you?
No, my love, no.
Oh johnny, oh johnny, I fear you are unkind
I love you far better than all of mankind.
I love you far better than words can ere express
Wont you let me go with you?
Yes, my love, yes.
Yes, my love, yes.