This has been bothering me for a while now: how is there a character with an Isish accent? Or Brittish or Russian for that matter?
I mean, Cait probably isn't from Ireland. If she were, I would expect the whole sea-voyage thing would have been included in the life story she spills all over you.
So what gives?
I prefer to think that somewhere in New England there is a town populated by the survivors of Vault 98, which was in turn populated entirely of first-generation Irish immigrants.
Perhaps similar national-origin vaults existed all across the United States, explaining the spattering of odd accents in a world where travel across the sea is so unlikely.