I responded to your other message earlier, but I do have more to add on Jeremiah Dugan Jr.My cousin did some research in Bantry, County Cork, Ireland, where we knew the Dugans were from, and found a marriage record for Jeremiah Sr and his wife, and baptism records for Jeremiah Jr and Ellen.The other three children were born in Montague Massachusetts.
From the parish of Bantry, diocese of Cork-Ross, Church of St Finbarr:
Jeremiah Duggan and Mary Croneen [Cronin] married 25 February 1843, witnesses were Daniel Shea and John Harrington
Jeremiah Duggan born 23 December 1843 and was baptised on 23 December 1843, parents Jeremiah Duggan and Mary Croneen, sponsors Michael Croneen and Ellen Crowley
Ellen Duggan born 14 December 1846, baptised 14 December 1846, parents Jeremiah Duggan and Mary Croneen, sponsors Humphrey(?) Neil and Mary Sullivan