My Grandfather was James Duignan. As I understand it, his family migrated from County Roscommon to Argentina where they raised horses. He came to the USA in the late 1800s, early 1900s. I also understand that he spoke Spanish better than he did English at the time of his arrival in the US.
He settled in the Bronx, NYC, and had five children, Ann (my mother), Marie, Stanley, James, and William.
My late uncle, James did considerable research on the family at one time, but no one knows what happened to his records. I do remember him telling me that the Duigans origionally came to Ireland from Normandy.