The Vikings were in North America, of that there is no reasonable doubt — although there was some touch-hole around here who argued against the Viking site at L’Anse aux Meadows by just digging in his or her little feet and gainsaying it, like Monty Python’s Argument Clinic. Despite the supposed evidence to the contrary, the Newport Round Tower is probably also PreColumbian. The climate turned on the Vikings, which cut into their population explosion, and they were left behind in the navigation and ship construction developments that swept Europe for various reasons. Even though there was at one time a Roman Catholic Bishop of Vinland, the Viking colonization ultimately failed, leaving us with, perhaps, Maine Coon Cats and some rune-inscribed stones.
I also wonder at the possibilities that the remains of other great civilizations lie well under water on the Continental Shelves, and bulldozed beneath the moraines and buried in outwash plains of the last ice age.
The puzzle is coming together, but there are a lot of pieces yet to be found.