John McHugh, born in 1816 in Ireland and Emigrated to New Brunswick Canada

I would like to find out specifically where my McHugh relatives were originally from in Ireland and have hit a brick wall.  I am also interested in finding out who my g-g-grandfather's parents are. 

I would appreciate any help anyone could provide.  I do have additional information if needed.

My great-great-grandfather, John McHugh, was born in 1816 in Ireland, but I don't know what county. He married Bridget McCullough McHugh on February 21, 1843, in Westmorland, New Brunswick, Canada. They had seven children in 18 years. He died in 1881 in New Brunswick, Canada, at the age of 65.  

Census information says he Immigrated from Ireland in 1829 and lists his Occupation as Farmer and that he Emigrated to New Brunswick in 1829. Listed in the 1851 and 1871 Census of Can living in Dorchester, Westmorland, New Brunswick. In 1851 Census, SARAH McSWEENEY, was living in household, listed as a 60 yo widow who lived in NB since 1844

My great-grandfather, John McHugh was born on June 22, 1845, in Memramcook, New Brunswick, Canada. His father, John, was 29 and his mother, Bridget, was 18. He married Elizabeth Healey in New Brunswick, Canada. They had ten children in 13 years. He died on August 28, 1924, in St John, New Brunswick, Canada, at the age of 79.