Controversy ensued over a performance given January 17, 1862 at Fairfax Courthouse, Virginia, for troops of the Army of the Potomac. The concert was intended for the First New Jersey Regiment, whose Chaplain, R. B. Ward, was a friend of John's, but many other troops attended the performance as well. The Hutchinsons sang a musical rendition of John Greenleaf Whittier's poem “We Wait beneath the Furnace Blast”, which was a recasting of the Lutheran hymn, “Ein Feste Burg Ist Unser Gott” (itself based on Psalm 46), and provoked quite a reaction from attendees who objected to the tune's anti-slavery lyrics.
https://en.wikipedia.org/wiki/Hutchinson_Family_Singers