Facts
John Turgeon was my father's maternal grandfather. Family legend has it that he was in the 1
st Iowa Cavalry during the Civil War. On the
internet, I've found that he was in Company D of the 8
th Iowa Cavalry Regiment. He married Abbie Pike on 29 Jan 1881 (records found on internet), and had at least two children: Harry M Turgeon, born c. 1886 (age 24 in the 1910 Census) and Myrtle Turgeon, born 1888, my paternal grandmother. The Bertrand Turgeon that Uncle Bruce mentions is Harry's son.
Cemetery records found on the internet show John T Turgeon, b. 1846, Military Service: GAR -Co. D, 8th Iowa Cav d. 19 Jan 1911, Source Book: LCC © 1990 - page W-102.
The 1880 Census shows a 35 year old John Turgeon living in Columbus City Township, in Louisa County, Iowa. He was born in Virginia, and so were both his parents. He was living in the household of William Ludlow, along with an Elizabeth Pike, age 69. Elizabeth Pike seems to be listed as mother-in-law to the head of the house, and so would be the mother of William's wife, Mary. Mary is probably the younger sister of Abi Pike, whom Turgeon married the following year. The part about Mary is pure speculation, since there is no other indication that Abi wasn't the youngest in her family.
There don't seem to be any other, earlier records of John Turgeon.