“Old John Brown's body lies a-moldering in the grave,
While weep the sons of bondage whom he ventured all to save;
But though he lost his life in struggling for the slave,
His truth is marching on.

Glory, Glory, Hallelujah!
His truth is marching on!”

–“John Brown’s Body”

Moldering means “rotting.”
Who are “the sons of bondage”?

slaveholders

enslaved people

all Americans