John Mitchell was probably the youngest son. Records we have examined provide a number of dates of birth, ranging from October 1833 to sometime in 1840. The most likely date of birth is circa 1837, as his age was given as 13 on the 1850 U.S. Census, but even this date should be treated with suspicion. All records indicate that he was born in New York, one indicating Rensselaer County. According to Aber & King's History of Hamilton County, the Mitchells and the Camps lived in Troy for a time, and John may have been born there.
Catherine (Benedict) Mitchell apparently died at some point before 1845, as this is when Michel Ajean (aka John Mitchell Sr.) remarried. This explains why a young John Mitchell was living with Asa Morse, an old acquaintance of Sabael Benedict, in Minerva in September 1850. Ten years later, in August 1860, John Mitchell and his cousin Samuel Benedict are boarding in the household of James Cosgrove of Indian Lake. Both are working in the lumber industry.
Mitchell was probably the John Mitchel who served in a Minerva-based unit (with his brother Peter and brother-in-law George Williams) during the Civil War. In June 1865, he is working as a hired hand on the farm of Jacob Waldron in the second district of Johnsburgh, and in July 1870 he is once again living in Indian Lake and working in the lumber industry, boarding with his niece Louisa (Williams) Palmer and her husband Charles. The family is living next door to the household Mitchell's cousin, Elijah Camp.
Throughout his life, John Mitchell stayed close to his Abenaki family, but also formed strong bonds with his non-native neighbors. In 1873 he married a white woman, Julia Wilson, (a newspaper account of the wedding erroneously identified Mitchell as "a full-blooded Indian of the Mohawk tribe," noting that he took Wilson "for his squaw") at the home of Elijah Camp. In January 1875 their first child, Edward, was born.