You'll need to check the 1850 US census for New York State. Most big city libraries have census indexes as do larger Family History Censuses. Look for Thomas (P) (Paul) Kewley age about 8.
That should give you one or more census entries to investigate.
I'm afraid Kewley is a fairly common Manx surname; there are several lines in the 1841 IOM census which was the first one on the Island.
Let us know when you get the father's first name and approximate age.