Edit: The second bit you posted above really sounds to me like whoever wrote it has an axe to grind with the actual material Wolter is presenting. I'm sure not every idea he throws out there is accurate, but neither is what Wolter shows in his series akin to unicorns. There may be some comparison to Ancient Aliens in the fact that the Ancient Aliens series is (in my opinion anyway) on the right track with its basic premise, but it is not produced as a scientific documentary but rather as entertainment and so its arguments are not as solid as its production techniques are.
There is plenty of evidence with or without Wolter, that the Vikings and other Scandinavians were here before Columbus (this is actually not such a huge issue historically because it is pretty well accepted already that the Vikings beat Columbus here anyway), and also evidence that the Templar, Carthaginians, Welsh, Romans, Sumerians and/or Babylonians, Egyptians, Chinese, Hebrews, Minoans, and of course all of the various "Native American" tribes, were here before Columbus (though not in that order
). The evidence is different for each of those cases but arguments can easily be made for any of them, and the only arguments against such ideas are often just that ancient ships would not have been able to cross the Atlantic, when this has already been disproved in modern times with recreations of the ancient ships.
Anyway lots of people are going to upset with America Unearthed simply because they don't feel comfortable with any changes to the historical narrative they have grown up believing, and these kinds of people are going to be attacking Wolter just to discredit what he says. But like I said, regardless of Wolter, the stuff he shows on the television program is most of the time already well-documented and he is just bringing attention to it from a wider audience in the same way as Ancient Aliens just brings attention to many pre-existing theories. These shows don't go into the amount of evidence that someone serious about this kind of thing might like them to, but it's for entertainment television and that has to be remembered too.