Hi Krissy,
There are actually two John Glen Dewars I've come across in North America. The first is the one b. 25 OCT 1871 Central District, Glasgow, Lanark, Scotland to JOHN GLEN DEWAR and HARRIET MCDONALD (per register of Scottish births listed at LDS site). He is the one who was the brother of two girls taken in by my husband's g-g-uncle and aunt, George and Florence (Brown) Elder, who lived in Williamstown, Glengarry, Ontario. The Dewar family is in the 1871 census with Alexander, age 2 and Mary, age 4. By 1881, Mary and younger sister, Ettie (Harriet/Etta) are at Govan House orphanage in Glasgow and Alex and John are at Mossbank Industrial School in Glasgow. Mary and Etta were among the Home Children sent to Canada in 1881 and Alex was sent there in 1885. I don't know when or whether John came as well. Mary married at Williamstown in 1887, naming the above parents and Etta is with the Elders in the 1901 census. I don't know if they also took in Alex or John.
There was another John Glen Dewar who I thought was the same person, but his dob doesn't work. He's b. 20 July 1877 or 1879, depending on source, and turns up in Montreal in 1901 census, then in Chicago in 1910 and the Pittsburgh area from 1920 onward. There's a John Dewar, age 3 who came as a Home Child in 1884, so maybe that's who this one is.
While looking for the name, I also saw a John Glen Dewar in a census in England, but didn't take down the specifics.
I hope that helps some.
Joy