The sheet music can be found at the Levy Collection (which doesn't seem to be working right now). I think this layout will make the structure of the song more clear:


WHEN THE WAR BREAKS OUT IN MEXICO I'M GOING TO MONTREAL
Words by J. Brandon Walsh. Music by Ernest Breuer.
Chicago: Will Rossiter, 1914.

1. Somebody told Sam Jackson 'bout the War in Mexico.
They said, "Your country needs you now, so grab your gun and go.
Go where the rifles crack and lead each mad attack."
Sam said, "I knew a hero once who got shot in the back,
And after all the folks had read about the charge he led,
They said he was a hero. Ain't it too bad he's dead?
Therefore, I must refuse to help Miss Vera Cruz.
I couldn't go to any war with just one pair of shoes."

CHORUS 1: "When the war breaks out in Mexico I'm going to Montreal.
On my forty-second cousin up in Canada I'm going to make a friendly call.
I'd like to be a hero in a suit of blue,
But my insurance policy is overdue.
When the war breaks out in Mexico,
Someone else can start fighting. I'm going to Montreal."

2. Sam Jackson said," my head and heart are very, very brave,
But when I am in battle, my two feet will not behave.
I had a fight one day; my head wanted to stay.
In spite of all my head could do, both my feet ran away.
A soldier on a battlefield can have lots of bad luck,
For when a bullet comes along, he might forget to duck.
So when the bugles blow, and all the soldiers go,
You'll see me going mighty fast, but not to Mexico.

CHORUS 2: "When the war breaks out in Mexico I'm going to Montreal.
A postal card will reach me up in Canada; I won't be coming home till fall.
'Bout my patrioticism [sic], I don't want to brag,
But I'll lean out of a window and I'll wave a flag.
When the war breaks out in Mexico
Just break the news to father that I'm going to Montreal."