Here's the full listing on the Nat. Geo. album mentioned earlier:

Various, Songs Of The Civil War, National Geographic, LP, ?00789, 1976

Tracklist:
A1 Day of Drums
A2 Dixie
A3 Wait for the Wagon
A4 I've Been in the Storm so Long
A5 The Homespun Dress
A6 Goober Peas
A7 Johnny Has Gone for a Soldier
A8 Richmond is a Hard Road to Travel
B1 The Southern Soldier Boy
B2 Follow the Drinking Gourd
B3 The Yellow Rose of Texas
B4 Marching Through Georgia
B5 The Battle of Shiloh Hill
B6 The Rebel Soldier
B7 Year of Jubilo
B8 Twilight at Appomattox

One fiddle/mando player is none other than citybilly Jay Ungar about six years before Ashokan Farewell which, thanks to Ken Burns, is now as cliché Civil War as the acacia to Africa.

Full credits are too much to list,
Discogs: Songs Of The Civil War, National Geographic

PS: I'd like to learn more about those Federal Government song pluggers as well. Plenty of shady dealings during the war but this one's news to me.