This comes from T. M. Marvin on rootsweb:

It is possible that Isaac may have been married prior to his marriage with Jane.  The 1840 US Census shows the code 010001-11001 for Isaac.  This indicates he was 35-40 years old, and his wife was 20-30 years old.  In his houshold he also had one boy age 5-10, one girl aged 5-10 and one girl less than five years old.  Isaac and family lived in the 14th Civil District of Washington County on land adjoining his brothers Charles, John and James Jr., and their father James Bacon, Sr.  Isaac was referred to as "Isaac of James" in legal documents to distinguish him from the other Isaac Bacon's living in Washington Co.  In 1867, Isaac purchased one-half of an undivided interest in 140 acres on the head of Sinking Creek (District 13) from Vina Bacon, wife of Edmond Bacon.  After Isaac's death in April 1869, a dower was laid off for his widow, Cynthia, and the remaining land given to his heirs.  Isaac's death is noted in the Bible of his brother Charles Bacon (1814-1894).  Descendants of Isaac are from James T. Dyke's account in "The History of Washington County".

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Isaac Bacon son of James and Magdalena Nimon Bacon was married three times.  (1) Jane Bacon daughter of Jeremiah or John of John Bacon brother to James above.  (2) Margaret "Peggy" Bayless  (3) Cynthia Hicks ; his last wife Cynthia was living on or nearby Sinking Creek.