There were Irish soldiers on both sides of the U.S. Civil War (the so-called Irish Brigades) and their ballads have continued to be popular to this day. Arguably my favorite one is here sung by David Kincaid (Irish-American), telling of the 11th New York Infantry and the 69th New York Militia, an Irish unit, at the Battle of Bull Run against the rebels (the tune mentions the charge upon the New York infantry by the Virginian Black Horse cavalry).

The Boys That Wore the Green - David Kincaid at Historic Richmond Town's Tavern Concert Series. - YouTube

Kincaid's ballads are well worth listening to but his brogue is a bit hard to comprehend.