I have recently been searching info on my great grandfather, Patrick Breen, Co. Kerry. He too lived in New York and enlisted in the Regular Army in 1855 in NY as a musician. He participated in all the major engagements of the Civil War and was discharged after 22 years in the Old Army. However, he was born in 1839 and died in 1909. Seems as though there were/are many Patrick Breens, including a few who served in the Civil War.