Classic Poem

I was the first fruits of the battle of Missionary Ridge.
When I felt the bullet enter my heart
I wished I had staid at home and gone to jail
For stealing the hogs of Curl Trenary,
Instead of running away and joining the army.
Rather a thousand times the county jail
Than to lie under this marble figure with wings,
And this granite pedestal Bearing the words, “Pro Patria.”
What do they mean, anyway?