Maybe this is it. (From a great CD "Johnny Whistletrigger: Civil War Songs of the Western Border" by Cathy Barton & Dave Para. (If you don't know about them, visit their website at
http://www.mid-mo.net/dpara/

BTW re: the thread about the top five folk albums, this one would certainly be on my list.

KNOT OF BLUE AND GRAY

You ask me why upon my breast, unchanged from day to day
Laying side by side on this broad band I wear the blue and gray
I had two brothers long ago, two brothers light and gay
One war the suit of northern blue and one of southern gray

One heard the roll call of the south and linked his fate with Lee
The other bore the stars and stripes with Sherman to the sea
Each fought for what he thought was right and fell with sword in hand
One sleeps amid Virginia's hills and one in Georgia's sand

But the same sun shines on both their graves o'er valley and o'er hill
And in the darkest of the hour my brothers they lie still
And that is why upon my breast, unchanged from day to day
Laying side by side on this broad band I wear the blue and gray