Your family seems to be in my database. A Jeremiah Duggan married a Mary Kenneally in Clontead-Belgooly Catholic parish in 1844. I show only children Elizabeth, Timothy (Thaddius)and Catherine, so they must have left the area after that. They were from the same townland, Ballingarry, as the ancestors of Bertie Ahern, the Prime Minister of Ireland. His cousins are still there.
The easiest thing for me is to e-mail you all the Duggans in my database as an Excel worksheet, i.e. attachment. Do you have Excel? I need your e-mail address.
Frank Thompson / NYCftcorkmdb@aol.com