Kerlin Family Genealogy Forum
I have strong suspicions that some of my early American Carlin ancestors changed their name spelling from Kerlin to Carlin in the late 18th Century when they migrated from southeast PA to KY, but I can't prove it.
For example, my g g g grandfather was Matthias Carlin, b 1770 in PA. I can't find really any Carlin families in PA at that time but plenty of Kerlins, including an older Matthias Kerlin.
If you've seen any alternate spellings in documents related to your Kerlins in those places and times I'd love to hear from you.