Pro Patria

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,
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?

-- From the "Spoon River Anthology"