Rathingle, if you knew your Irish / American history, they didn't have a choice (most of them at any rate! Straight of the ship and rounded up like sheep and forced into joining the ranks. A lot of 'old' Irish ballads even spell it out quite clearly.
BUT then again, in every war back then, the Irish had a hand in it. We like a good scrap, we do! Of course, things are different now, we are the peace makers of the NEW WORLD!! and if you care to disagree, please step outside and I will give you a QUICK but SHARP lesson!!!!! EOIN