John Hassett Sr. b.c.1806 Ireland m. Catharine Batterby b.c. 1800 Ireland Kids Ellen, Mary, John Jr., Catherine Emigrated from Dublin, Ireland Arrived Castle Garden, NY, 26Mar1849
Allegedly Married Clonmellon Parish, County Westmeath or County Meath, Ireland John Hassen m. Catherine Battersby 1835
Also baptized in parish: Eleanor Mary 1839 Catherine 1847
"There are baptisms of a Mary 1839 and a Catherine 1847 to parents of those names in Clonmellon RC parish, which spans the border of Meath and Westmeath. They are in both counties' sections of www.rootsireland.ie.
In the same parish is a marriage of Catherine Battersby and John Hassen in 1835 and baptism of an Eleanor Hassan (ending "an" this time) to that couple. Given the name combination wouldn't be common, the timings and all in 1 parish there's a very good chance it's all the one family. The Hassan record could be a mistranscription of Hasset. Would be interesting to see the original but http://www.nli.iehttp://www.nli.ie hasnt put these parish register images online yet even though they were planning to."
Only other notable Hassett in the area at the time is a Phelim Hassett, listed in Griffin's Valuation. I question whether they are related. ISO DOB of Phelim. There is a Phelam Hassett who immigrated to US, listed in Castle Garden records.
Lots of Battersby in Westmeath, one of the most prominant families does not list a Catherine but the head of household is a Sheriff.