Since I was there in the mid-70's when it was in full swing, I have some experience with "the troubles", in liaison with 62 Commando in Belfast, Antrim and Derry. They were dark times and thank God, they have passed. But St. Patrick's Day brings out a few memories.
And on the lighter side of things.
There is a lot of green beer served in the US and there will be fights breaking out in Irish bars/pubs by mid-evening over small (imagined) slights -- of the sort that one would see in Ireland in the normal course of life. Except that they don't drink green beer in Ireland.