... continued:
I searched and searched and when I could find no more, I began looking for the unit rosters by searching for his Captian's name (Thomas Collimer) and his Colonel's name (David Rogers). Under a search for Colonel David Rogers:
https://duckduckgo.com/?q=%22colonel+david+rogers%22+war+1812&t=brave&ia=web
I saw that the first link was to a WikiTree profile for Michael Van Wagoner. I immediately recognized the surname: John Miller's wife Marjery DeGraff's family intermarried with the Van Wagonen/Wagoner family.
I pulled up the profile and immediately, in the bio, I read:
He fought in the War of 1812, being enlisted on September 8, 1814 in New York in the Captain Thomas Collamer company of Detached Milition [Militia] in the Regiment of Infantry commanded by Lieutenant Colonel David Rogers. He served until December 11, 1814, and was paid a total of $16.77.[2]
I entered Marjery's WikiTree ID into Michael Van Wagoner's relationship finder and sure enough:
Michael and Maria are second cousins
Michael Van Wagoner and Maria (DeGraff) Miller are both descendants of Evert Van Wagenen.
1. Michael is the son of Michael Van Wagoner [unknown confidence]
2. Michael is the son of Jacob Van Wagoner [unknown confidence]
3. Jacob is the son of Evert Van Wagenen [unknown confidence]
This makes Evert the great grandfather of Michael.
1. Maria is the daughter of Abraham DeGroff [unknown confidence]
2. Abraham is the son of Marretjen Van Wagenen [unknown confidence]
3. Marretjen is the daughter of Evert Van Wagenen [unknown confidence]
This makes Evert the great grandfather of Maria.
So we learn that John's wife's second cousin is in his same militia unit. Michael and John have probably known each other their whole lives.
I checked the profile manager of Michael Van Wagoner against my profile in the relationship finder and I was surprised to find that we weren't related. She isn't related to Michael either. Through the connection finder I was able to see that she is a distant in-law. She probably, on a lazy Sunday, put in lateral relatives - spouses of distant cousins, their kids, parents, siblings, etc. When she gets close to a 5,000 profile management count, these will probably be the first profiles she orphans.
And because she created this profile, and took the time to document his war service, it gave me another validating piece of evidence towards proving that my 4th great-grandfather is a War of 1812 veteran.
I suppose that this is what I love about genealogy, looking for clues, trying so many locked doors, and then the satisfaction when one opens. And because another WikiTreer took the time to create that profile, the last door was unlocked for me.