Flanagan (Flannagan, Flanigan, Flannigan)

I'm looking for birth, death, marriage. relatives, or all the information on the family of Owen Flanagan (b 1799) and his wife Johanna (b1798).  Her last name begins with an N and might be something close to Neilsen, Neilson.  The record I have that names her is very difficult to read.    Each of these children claim to have been born in Dungourney, Cork as well: Mary (b1826), Owen (b1832), John (b1836), and Michael (b1843).  

The entire family immigrated after 1826 but before 1854 because that's the year Mary marries Thimothy Callahan (b1830 in Ireland) in St Mary's Catholic Church in Portland, Middlesex, Connecticut, USA.  Timothy Callhan has an older brother named William (b1822 in Ireland). 

Owen Flanaga worked in the brownstone quarry not far from the property he owned on Ferry Rd in Portland by at least 1854.  The house was large enough for two Flanagan families and the Callahan family to live in. 

All the dates are approximate.   I suspect this much data at least suggests that Owen was a man of means.  Over 18 years, you move 6 people from Ireland to USA and own your home.  I did search for immigration records but didn't find any where an entire Flanagan family immigrated.  

Thank you for any assistance you can render!

Patricia D Mulholland (a third great grand child of Owen Flanagan)