Most of this you will have picked up from previous replies but it is easier for me to keep it all on one page so I have relooked it up.
James Cormack, 24, b London England, s/o David Cormack and Elizabeth Cruickshank, married GRACE BENNING, 24, b Marolin England [should be Malling] d/o George Benning and Sophia Addley, 19 July 1902 Manhattan New York, New York US.
I could not view the original.
I don't know if London is the correct birthplace as other places indicate Scotland for James but at least his parents are named.
This is on familysearch.org
David Cormack, married Elizabeth Duncan Cruickshank 07 June 1860 Marylebone Middlesex England. Father's name David Cormack. Spouse's father's name John Cruickshank.
Elizabeth Duncan Cormack's death is registered Marylebone December 1/4 1884.
On all the following christenings, mother's name is given as Elizabeth Duncan, fathers David Cormack
Elizabeth Cruickshank Cormack , chr 17 May 1865, St Luke Westminster London born 26 Jan 1865. Father: David Cormack, mother: Elizabeth Duncan
Marion Swanton Vain?, b 14 Jan 1863, chr 29 Apr 1863 at St Luke's
Annie Imrie, b 29 June 1861, chr 21 Aug 1861 at St Lukes
JAMES, no birthdate given, chr 03 May 1878 at Westminster, MIddlesex
Donald Graham, no bdate given, chr 03 May 1878 at Westminster
Jessie Bain, no bdate given, chr 03 May 1878 at Westminster
Jessie married a Cormack and the last census she is on is in Hendon Middlesex 1911 and she is widowed, aged 44, maternity nurse.
Her husband Aitken W died 1901.
A Jessie B Cormack, aged 58 died June 1/4 1926.
Elizabeth Cruickshank Cormack married Sept 1/4 1892. Don't know who her husband was.
On 1841 census Midlothian there is a David Cormack ,aged 2, b England 1839.
Could be him or not.
1881 census Marylebone London England
David, 42, dentist, b Lancaster
Elizabeth, 46, b Scotland
Anne T, 19, governess, St Pancras MIddlesex
Marion, 18, dressmaker, "
Lizzie, 16, millener, "
Jessie, 14, millener, "
Donald, 5, scholar, b marylebone
James, 3, scholar, b "
1891 census Marylebone London England
40 Queen Anne Lane Cavendish Square, Marylebone
David, widow, dentist, 52, b Manchester
Annie M, dau, 29
These are all been scratched out. All listed as daughters.
Then below is
David Alexander, son, 22, dental student
Donald G, son 15, scholar
James, 13, scholar
Charlotte Smith, servant, 19,
Another Cormack son that I cannot read that has been scratched out.
Maybe the ones that were scratched out have emigrated.
1901 census Strood England
Grace Cormack, 24, widow? and son James, aged 1 are housekeeper with a Richard Head.
Birthdate fits with James' year of birth.
1901 census Strood
A Gordon Benning, 3, stepgrandson is with Sophia and George Addley.
Grace's parents names are George and Sophia Benning so maybe Sophia remarried.
Gordon's is registered at birth as Gordon Cormack Benning at Strood June 1/4 1898.
No birth rego found for James under either name.
Then Grace turns up in 1908 on ship Pretorian from Liverpool to Halifax, 31, wife, b England with daughter Jessie, 4yrs3mths going to Montreal and stamped "Ret'd Canadians".
1911 ship Dominion from Liverpool to Halifax and Portland.
Grace, 33? lived in Montreal last 6 yrs, b England, married, went over to England in November.
Gordon 11 and James 10 b England. Have been in school in England for 2 yrs
Jessie, 6, b Canada, went to England with mother in November.
1911 census Pickering Ontario South
Grace, widow, b April 1877, England, immigrated 1900, market gardener
Gordon, son, March 1898, 13, England, at school
James, son, Jan 1900, 11 England, "
Jessie, daugh, 6 ,Sept 1904, USA?, immigrated 1900
Herbert A Wilmor, half brother, April 1869, 42, immigrated 1905, gardener
Ivy B Wilmore, half niece, 18, Dec 1892, England
Marriage for Jessie Patricia says she was born Twonytown? NY.
SHe married in 1927 to William Ewart Bell and her father was given as James Cormack born Edinburgh Scotland.
1921 census Port Perry
Grace, 46, England, immigrated 1895?, nurse
Jessie, 17, b USA, immigrated 1905
1921 a Grace Cormack and James Swan were witness at marriage of James N Cormack and Pauline A Geliner.
Grace Cormack , d/o George Benning and Sophia Taylor, nurse, 44, b Rochester England, widow married James Swan 54, carriage maker, 9 May 1921 at Port Perry Ont.
Bride 's father was born Buckinghamshire England.
James Swan died 8 December 1946 at Port Perry. Grace was the informant.
Grace b 1875, died 1960, buried Port Perry