David appears in the 1850 census as head of the household living in Niagara, Niagara, NY, USA shortly after his father John died:
David NIBBS 23 Eng
Ann NIBBS 53 Eng
Naomi NIBBS 30 Eng
Charles NIBBS 28 Eng
Ellen NIBBS 20 Eng

Naomi may well be an error in the census or the transcription for the name Nehemia. Nehemia was a boy.
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We can also see David and his family at the 1860 census, living at Niagara, New York.
David Knibbs 31 Boatman England
Mary Knibbs 25 New York
Edgar Knibbs 6 New York
Roy Knibbs 3 New York
Francis Knibbs 8 months New York
Abigail Whiteman 64 Servant Connecticut

David's real estate was valued at $500 and his personal estate, $1,000
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David can be seen at the 1870 census living at Niagara, Niagara Falls, New York, USA:
KNIBBS David 43 Engineer of Boat Egland
KNIBBS Mary 35 Keeps House New York
KNIBBS Edgar 16 New York
KNIBBS Ray 13 New York
KNIBBS Louisa 10 New York
KNIBBS Minnie 8 New York
KNIBBS Lruae(?) 1 New York (presumably Isaac)

I note that Louisa in 1870 is recorded as Frances in 1860 and 1880.
David's real esatate was valued at $1,500
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David and his wife Mary appear in the 1880 census living at Niagara, Niagara, New York with their 5 children:
David KNIBBS Self M Male W 51 ENG Engineer ENG ENG
Mary KNIBBS Wife M Female W 43 NY Keeping House NY NY
Ray KNIBBS Son S Male W 23 NY Works In Pulp Mill ENG NY
Frances KNIBBS Dau S Female W 19 NY At Home ENG NY
Minnie KNIBBS Dau S Female W 17 NY At Home ENG NY
Isaac KNIBBS Son S Male W 10 NY At School ENG NY
Charles KNIBBS Son S Male W 8 NY ENG NY
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Information I have been given by Leslee Sears, the great-granddaughter of David's daughter Minnie suggests that David Knibbs was a ship's captain on the Great Lakes. She was told that by her own father.
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David's wife Mary can be seen in 1900 as a widow, living with their son Isaac.

We can see Mary in 1900 living on Ninth Street at Niagara Falls City, Niagara, New York with her son Isaac and his family:
Isaac Knibbs Head Aug 1868 New York, Plummer and ???
Ada D Knibbs Wife June 1874 Canada
Alace M Knibbs Daughter Sept 1894 New York
Mary Knibbs Mother January 1833 New York