"Good Old Rebel Soldier", "The Battle of Bull Run", "Bonnie Blue Flag" are good alternate perspective songs on the Civil War.

Seeger's Union songs are great reflections of the labor battles and socialist waves of the Thirties -- Union Talkin' Blues, Which Side Are You On?, Get thee Behind Me Satan, The Union Maid. Black White and Tan Blues is a heatbreaker. Bourgeois Town (Leadbelly) is another.

There are a number of good songs from the Western expansion and the building of rail West, including John Henry, Pat Worked on the Railway, Drill Ye Tarriers Drill, and the great Lomax collection of cowboy songs. I would try hard to dig up some songs of battle and suffering from the Amerindian side too. Not my field of expertise.

I have said before that it is my believe that folksingers, as often as not, are really time travellers who just happen to pop into this coordinate system we call the present to file reports!