Hi,

It is interesting to me that DNA tested amongst some Native American people a year or two ago showed a Greek origin.

Hello.
That Greeks or other seafarers may have reached the land we call America in pre-history is quite possible. Thor Heyerdahl averred that the Egyptians sailed from North Africa to Central America. He demonstrated how this could be done by recreating such a voyage.There is some, though slight evidence that some Phoenecians circumnavigated Africa. However when comparing the sounds of words in order to determine their origins one can easily find oneself in deep water. A case in point. You say " Minneapolis is the "polis" of the Minneans, ". Whereas it is more plausable that -"Minneapolis," a combination of a Greek term for "city" and "minne," a term from Lakota, the language of local Native Americans, meaning "of the waters." That Minni or Minne is Lakota for 'Water' is easily demonstrated. 'Polis' is undoubtedly 'Greek'. The City Founders in the early years of European expansion in the land now known as the U.S.A were fond of using classical names for their new 'cities'.
Is 'Philadelphia' therefore an old Greek City State ?
Etymology is full of pitfalls.

The idea of America certainly existed to some extent in the Greek Consciousness - the Vera Historia ends with Lucian "discovering America" so to speak, but as little more than a legend.

It's certainly an interesting idea.

There is so much that has been lost to history and prehistory. The more advanced archaeological techniques become the better chance becomes of rediscovering many of the ideas and past realities that have been lost.

Always try to keep an open mind. Even if one might not accept a theory doesn't mean that the entire theory is false. I have found that there is some truth in theories just as there are many truths in the ancient Mythologies.

actually we know for sure that the greeks knew of america. when plato starts to describe atlantis in Timeaus he said this

"For it is related in our records how once upon a time your State stayed the course of a mighty host, which, starting from a distant point in the Atlantic ocean, was insolently advancing to attack the whole of Europe, and Asia to boot. For the ocean there was at that time navigable; for in front of the mouth which you Greeks call, as you say, 'the pillars of Heracles,' there lay an island which was larger than Libya and Asia together; and it was possible for the travelers of that time to cross from it to the other islands, and from the islands to the whole of the continent over against them which encompasses that veritable ocean. For all that we have here, lying within the mouth of which we speak, is evidently a haven having a narrow entrance; but that yonder is a real ocean, and the land surrounding it may most rightly be called, in the fullest and truest sense, a continent. Now in this island of Atlantis there existed a confederation of kings, of great and marvelous power, which held sway over all the island, and over many other islands also and parts of the continent.[2]"

if you look at it geographically you can see that where atlantis is supposed to be is right between america and europe. this "continent" that he talks about is in fact america, and he tells us clearly that people visited it.