Or, try this. Celtic presence in America before Leif Erickson, before Brendan the Navigator, even before the Incarnation? This article here by Michael McCormack on the First Christmas Card is quite convincing.
Father Longenecker: Something inside me thrills when the received account of history is re-written: when you discover that Henry VIII was not a “jolly old Englishman who had an eye for the ladies…” but was in fact a lecherous tyrant, or when you realize Elizabeth I ruled her country as a police state similar to Soviet Russia. Full article is here.