My great-great-grandfather was Duncan Carmichael, born in Killarrow around 1830. His parents were Archibald Carmichael and Isabella McDougall, and the family moved to Ontario when he was a child (late 1830s). From there, they moved to Michigan in the 1850s.
Archibald Carmichael's parents were Angus Carmichael and Elizabeth Stewart. Isabella McDougall's parents were Duncan McDougall and Christian Graham. I haven't been able to go back further than that because of the naming practices confusion.
Islay Families: Carmichael, McDougall, Stewart, Graham.