I am also researchin the Breen family - I live in Ireland, CO. Wexfrod, wjere a large family of Breens lived in Oldcourt, out side New Ross. I believe at least four of them went to the US in the late 1800s, early 20thc. I have located two - David Breen, who went to Jackson Heights New York, and his sister Ellen also went there.
I have lost all trace of a brother Robert, who I believe was born around 1869. I think he may have married a Mary, and may have had two daughters, Margaret & Sarah and a son William. But this may be in accurate.
I have reason the believe that he may have gone to the Boston Area, and he had a sister Mary / Marie / May who travelled out to him after a scandal here in Wexford. Id love to know if anyone knows anything about them!!