I have not much else to go on but I know a lot of MCDERMOTTs come from Roscommon!!!?
James MCDERMOTT and Nancy CAULEY had at least one daughter, Ann MCDERMOTT born 1825 - Ireland, died 1894, Massachusetts. She ended up marrying Patrick PURCELL, son of Christopher PURCELL and Ann HIGGINS in Quebec, Canada 1844.
I know, not much to go on but there is where my tree stops =(