This is a copy of a blog post I wrote - Finding James Patterson:

One of the challenges I had searching my family tree trying to ascertain who James Patterson was.  With a common name like that, there were quite a few people to choose from.  Rather than document the long round process I took to finally decide, I will layout the facts, and the decisions I had to make.

Discovering James: Joseph MacPherson, my great, great-grandfather married Lizzie Patterson in St. Stephen's Church in the township of Bathurst, Lanark County on October 2, 1884.  Her parents names were listed as James and Mary Patterson.  A few other clues from this document are that Lizzie was 21 years old, born in South Sherbrooke township, and also resident there when married. Also, one of the witnesses to the wedding was Mary Patterson, which may or may not have been Lizzie's mother.

Joseph on the other hand is listed as 28 years old, born in and resident of Olden township. His parents names are Duncan and Mary MacPherson (actually listed as McPherson), and a Richard MacPherson (probably Joseph's brother) was a witness to the wedding. 

St Stephen's Anglican Church: From the Anglican archives (https://www.archeion.ca/st-stephens-anglican-church-brooke-ont):

Services were being held in Bathurst (later known as Brooke) by 1849 and the wooden church of St. Stephen's was opened on September 26, 1867. The church was consecrated on September 16, 1876 by Bishop J. Travers Lewis. By 1909, money was being raised and the new stone St. Stephen's was built on land purchased from Mr. Neil Blair and opened on December 8, 1912. 

More James Patterson info: At this point we have a name only.  But in 1899 we have record of a 68 years old James Patterson who died in Olden Township a little west of South Sherbrooke and Sharbot Lake.

We can see here that he was a farmer that lived at lot 16, concession 10. 

This just happens to be the address of Joseph MacPherson in the 1885 Frontenac Directory. 

Joseph MacPherson also was listed as the 'person making the return' on page 2 of James' death record.

Interim Summary: We have a James Patterson born n 1830-31, married to a Mary Patterson who once lived in South Sherbrooke township. They had a daughter Elizabeth "Lizzie" in 1862-63.

Problem 1: I could not find a James Patterson born in 1830-31 with a wife named Mary.  Well, not one that ever lived in South Sherbrooke, Lanark County, Ontario.

Problem 2: There were two Elizabeth Patterson's born in Sherbrooke Township in the 1860's according to the 1871 census.  According to the 1901 census, we need one born July 1, 1863.  So the younger Elizabeth was 8 in 1871.  Turns out the other one is her aunt, only two or three years older than her. 

Problem 3: The problem with both these options, is that neither of the mother's names was Mary.  The first is Ellen, second is Elizabeth.  However, a second look shows James jr. and Ellen have a daughter with the name Mary Ellen who was two years old in 1871.  It is very possible that Ellen has a first name Mary also. 

Problem 4: So what about James. Ellen's husband was born in 1840-41, not 1830-31.  Elizabeth's husband was born prior to 1820. So a double check of the death record is in order - no, it still says 68 in 1899.  Still, perhaps it was an error when written down and should have been 58.

Further info: Although the Patterson's lived in South Sherbrooke, the 1881 census shows them living in Oso township.  Both the 1871 and 1891 census has them in South Sherbrooke.  Did they move for awhile? or were transplanted for a reason?  Not sure.  Oso township is really close to Olden, and also where Joseph McPherson's grandfather and extended family lived.  Three years after the census, Joseph and Lizzie were married. 

Conclusion: Despite the age issue for James, because Lizzie was from South Sherbrooke, her father's name is James, and mother is possibly Mary (Ellen). I think it is very likely that James and (Mary) Ellen Patterson are the correct parents of my great, great-grandmother Lizzie MacPherson.

Documents:

1885 directory Joseph MacPherson address Olden township

James Patterson death record