Cornelius Roche born about 1842 New Castle, Limerick - any information?

hello, doing some family research.  Our oldest known Roche relative is Cornelius Roche born about 1842.  He gave his place of birth as New Castle (Limerick) on an immigration card when he entered the United States for a short visit in 1910.  He left Ireland and settled in Canada.  He married a Mary Ellen O'Dwyer (born 1833 and died 1889, and whose tombstone records she was a Native of Co. Tipperary).  I don't know where they were married.  Their first child was born in Pickering, Ontario (the Toronto area) in 1862 (Catherine Roche).  Other children included Mary Ellen; Hanna Theresa; William Henry; James D; Marguerite; and Cornelius John.  These children were all born in Ontario, most in Watford, Lambton, Ontario, Canada.  Cornelius died in Detroit, Michigan in 1919 and was buried in the family plot in Watford, Ontario where his predeceased wife (Mary Ellen O'Dwyer) and several other daughters were married.  New to genealogy searching.  If anyone can give some advice on records for Cornelius or Roche families born in New Castle circa 1842, I'd appreciate it