Here's one:

My name is Tim McDonald, I'm a native of the Isle,
I was born among old Erin's bogs when I was but a child.
My father fought in "'Ninety-eight," for liberty so dear;
He fell upon old Vinegar Hill, like an Irish volunteer.
Then raise the harp of Erin, boys, the flag we all revere--
We'll fight and fall beneath its folds, like Irish volunteers!

The Battle of Vinegar Hill was on June 21, 1798. Assuming that the singer was conceived just before the battle, he would have been 62 or 63 at the outbreak of the US Civil War...a bit old for soldiering. Not impossible, but very highly unlikely.