I am looking at my 2nd great grandparents, Patrick McCarry and his wife, Margaret O'Connell. We see them in the New York State Census for 1875.
|1875 New York State census, Montgomery, Orange County, population schedule, p. 15, dwelling 108, family 130, Patrick McCarry; digital image, Ancestry.com (www.ancestry.com : accessed 26 Oct 2015)|
In the 1930 U.S. census the information changes. This is the census record for their son Patrick who was born after the 1875 census.
|1930 U. S. census, Philadelphia County, Pennsylvania, population schedule, Philadelphia, p. 8B, dwelling 90, family 108, Patrick McCary; digital image, Ancestry.com (www.ancestry.com : accessed 26 Oct 2015) ; citing NARA microfilm roll 2103.|
This says that Patrick was born in Pennsylvania, ( he was actually born in Connecticut), and his parents were born in Northern Ireland. Living with Patrick and his wife Frances are her three sisters. Frances and her sisters were all born in Northern Ireland. So without giving a specific location in Ireland, it does narrow it down a little.