Hi. I'm not related to this family.Are you sure William was born around 1890?This might be them in 1916:
1916 Canada Census of Manitoba, Saskatchewan, and Alberta about William Agnew Name: William Agnew Gender: Male Marital Status: Married Age: 40 Est. Birth Year: 1876 Birthplace: Ontario Home in 1916: 27, Prince Albert, Saskatchewan Address: 48, 23, W2, Birch Hills 460 Racial or Tribal Origin: English Relation to Head of Household: Self Spouse's Name: Nina Agnew Sub District Desc.: Townships 48 to 54, inclusive, ranges 23 and 24, W. 2. M., including the river lots Household Members: Name Age William Agnew 40b. 1876 Ontario; farmer Nina Agnew 23 -wife- b. 1893 Ont. Cecil Agnew 4 -son- b. 1912 Sask. William A Agnew 2 -son- b. 1914 Sask.
Two households down is a George Agnew, b. 1877 Ont, wife Margaret, b. 1878 Ont, & children Alma, b. 1907 Ont, Dorothea, b. 1910 Ont. & Pearl b. 1913 Sask.
They may be related.Here is Alma's birth record:
Ontario, Canada Births, 1869-1913 about Agnew,alma Agnew Name: Agnew,alma Agnew Date of Birth: 6 Feb 1907 Gender: Female Birth County or District: Lanark Father's Name: George Agnew of Smith Falls, C.R.R. Employee Mother's Name: Maggie Wilson
Ontario, Canada Births, 1869-1913 about Marie Dorothy Agnew Name: Marie Dorothy Agnew Date of Birth: 14 Apr 1909 Gender: Female Birth County or District: Lanark Father's Name: George H Agnew Mother's Name: Margaret Wilson Married: Sep 1904 Smith Falls
Here is the marriage for this couple:
Ontario, Canada Marriages, 1801-1928 about George Herbert Agnew Name: George Herbert Agnew Birth Place: Montague Age: 26 Estimated Birth Year: abt 1878 Father Name: Robert Agnew Mother Name: Mary Prescott Spouse Name: Maggie Wilson Spouse's Age: 25 Spouse Birth Place: Montague Township Spouse Father Name: Henry Wilson Spouse Mother Name: Elizabeth Scharf Marriage Date: 7 Sep 1904 Marriage County or District: Lanark
Here is George's birth record:
Ontario, Canada Births, 1869-1913 about George Agnew Name: George Agnew Date of Birth: 17 Oct 1877 Gender: Male Birth County or District: Lanark Father's Name: Robert Agnew, farmer, Montague Mother's Name: Mary Prescott
Although there is not a birth record for William Agnew, the family in 1891 does have a William Agnew, b. 1874:
1891 Census of Canada about William Agnew Name: William Agnew Gender: Male Marital Status: Single Age: 17 Birth Year: abt 1874 Birthplace: Ontario Relation to Head of House: Son Religion: Methodist French Canadian: No Father's Birth Place: Ireland Mother's Birth Place: Ontario Province: Ontario District Number: 84 District: Lanark South Subdistrict: Montague Household Members: Name Age Robert Agnew 55 -widower- b. 1836 Ireland Elizabeth Agnew 23 -dau- b. 1868 Ont, fath b. Ire, moth b. Ont. Thomas Agnew 21 -son- b. 1870 Ont, same Henry Agnew 19 -son- b. 1872 Ont, same William Agnew 17 -son- b. 1874 Ont, same ** Minnie Agnew 15 -dau- b. 1876 Ont, same George Agnew 12 -son- b. 1879 Ont, same ** Maria Agnew 40 -sister- b. 1851 Ont, par b. Ire
In 1881 the family is living in Montague, Lanark, and William is listed as William A. Agnew, b. 1874
Not sure if this is your family.Can't prove it.But, it's a lead.Hope this helps.Annie