Jamie, you are correct! The song is from a Confederate viewpoint, by a rather unredeemed sort--kind of like the "I'm a Good Old Rebel" type of guy, if you don't mind me pointing that out.

My impression as a kid some 40 years ago, knowing as little now of the reference as I did then, thankfully joined by the rest of y'all, is that the singer's viewpoint was that of a captured soldier who would've busted parole at his first opportunity. Again from memory:

"The Yankees took me prisoner,
They used me rough it's true,
They stole from me my knapsack
And the took my blanket too.

"So lay 10 dollars down, or 20 if you choose,
For I can whip the Yankee that stole ol' Abner's shoes!

"The Yankees took me prisoner, and if I get parole,
I'll go right back and fight 'em, I will upon my soul!"

"So lay 10...etc.

Very interesting, such a feisty little song. I got the impression that Abner was a local Confederate officer who managed not to get caught with his pants down--or off--like my kinsman, C.C. Washburn, did by N.B. Forrest in a rather famous family episode in which it was demonstrated that, in the midst of such carnage, men of both sides could upon occasion still act with chivalry towards one another.