John McKenna and Mary Duffy

Searching for information on my great-grandparents, John McKenna and Mary Duffy, believed to be from either Tedavnet, Errigal Trough, or Donagh (cross-posted).

Facts I know about John:  He lived in Lot 65, Prince Edward Island, Canada just prior to his death in late 1875/early 1876. According to his will he had 4 children: Margaret (b. 1861); Francis (b. 1963); Mary Ann (b. 1866); and, Elizabeth (b. 1868). His first wife, Mary Duffy of Monaghan, was the mother of these children. Her obituary said she emigrated to PEI in 1840 with her family.  Mary died in 1870, leaving John with 4 young children. In 1872, he married Bridget Hickey.

Guesses about John: Born about 1825-1840, believed to be in Tydavnet. He likely married Mary Duffy around 1840 (based solely on the birthdate of their oldest child in 1861).  Based on the name of his son, his father may have been Francis McKenna. There is a Francis McKenna in the 1841 PEI census for lot 65. He is a farmer in a household with one male age <16 (John?), 1 male 16-45 (likely Francis), and 1 female <16. The census record said 4 passages to PEI had been paid for indicating Francis' wife may have died in transit.

Possibility: The Tedavnet Catholic church parish records show a Joannes McKenna, baptized 12 Mar 1837, son of Franciscus McKenna and Honora McQuade. The church record says the family lived in Derecat (believed to be Derrynagad/Dernagad). If this is 'my' John McKenna, he would have been 23 years old in 1860, at the time of his estimated marriage to Mary Duffy.

Any help would be greatly appreciated. While it is wonderful knowing/guessing that John, like all but 1 of my paternal great-grandparents, was from Monaghan, it would be even more wonderful knowing who is parents were and where they lived before John appears in Canada.

Many thanks,

Kathleen Clarkin Foley