My great grandfather was John Cosgrove born 1864-1945. His father was James Cosgrove. They were in Ballyhaunis, county Mayo. He emigrated to Boston Massachusetts in 18-- not sure. He settled in Fitchburg. I have not researched him thoroughly yet. He married Bridget Morley and had 8 children. I'm not sure if there is a connection with your Cosgroves, but it's not a popular name.
Maybe his family moved over towns?