I'm trying to track down information or the origins of my 3rd great-grandfather, Bernard 'Barney' Donahue. He was born around 1810 in Ireland, and his gravestone says he was born in 'County Donegal, Ireland'. His death certificate leads me to believe his parents were Bernard Donahue and Bridget Dougherty, and I think Barney emigrated to the States around the time he turned 30, so in 1840ish. He lived first in New Jersey, where he married an Anna Malone and had his first child, John. By 1846 though, he was living in the northern United States in Milwaukee, Wisconsin. I suspect he also had a brother, Francis, probably born in 1811 or so. I'd appreciate any help or pointers about where to look next, as I'd love to find out where in Donegal he's from.