Three hundred thousand Yankees
Lie dead in Southern dust...

The most withering verse I know (suitable only for singing to historical societies really, as a measure of the bitterness of that time) goes,

And when the war was over
I joined the Ku Klux Klan
And for the Glorious Union
I still don't give a damn
I love to see a nigger
A-hanging from a tree
But if it was a Yankee
It's all the same to me.

That came from an old book in an Atlantan library.