All that I know at this point about the Irish origins of the three men is the following:

1. Christopher Gibson's son James reported his birthplace as Armagh when he married 8 Sep 1870 (in Pickering to Janet Smith). Christopher (birthdate unknown, but probably older than John, so about 1810) had married Elizabeth Gray in Northern Ireland about 1833. They had three known children there: Ellen (c 1834), Thomas (c 1837) and James (c 1839). By about 1842-1843, they were in Canada, when their fourth child Christopher was born.

2. John Gibson's son Christopher's daughter gave the birthplace of John (born c 1812-1813) and his wife Margaret (Sprout) as County Down on the 1929 death certificate of her father. John and Margaret married in Northern Ireland about 1835 and had three known children there: Jane (c 1836), John (c 1838) and Margaret (c 1840). By about 1842-1843, they were in Canada, when their fourth child Sarah was born.

3. Thomas Johnston is the one about whom I know the least. He was born in Northern Ireland about 1800-1802. So he was about 40 when he married Christopher's widow. When did he come to Canada? Had he lived elsewhere in Canada before coming to Pickering? Had he been married before? Did he have other children? Did he have family in Pickering Twp or nearby? Where in Northern Ireland was he born? All of these questions remain unanswered with no clues. The only bit of information is that the 1851 census does not show any other Johnston children with the family; so if he did have other children then they were not with him in 1851 (when he was almost 50 so that his children would almost certainly be grown and have families of their own).