Buffy Sainte Marie - "My Country 'Tis of Thy People You're Dying"

It's probably the most harrowing protest song ever written, and among other things mentions the occasion on which the US Army traded blankets to some starving Native Americans for their land, said blankets having been taken of dying soldiers in a smallpox ward. That's what you call killing 2 birds with one stone.

Also, "Bury My Heart At Wounded Knee", also by Buffy Sainte-Marie, about much more recent events.