Certainly ... modern boundries are too recent.
Did you know that the the Creek/Muskogee Indian population (Florida) has a lot in common with a tribe, their tribe, along the Amazon side of the Andes? They both Speak Quechua! And Quechua is even spoken down through and into Bolivia. They both drink the same tea, and the bush that the leaves come from seem to have been brought only to Florida. And their style of dress is the same, and especially the patterns.
I imagine that Quechua was spoken from that area, across the Amazon or along (or underneath!) the Amazon border up through Venezuela, and then up across the Antilles Islands to Puerto Rico, The Dominican Republic, to Cuba and then to Florida. And that those people/race existed along that whole stretch.
But then you might or might not know that Peru has some definite Chinese influence, and that the Spanish explorer Orellana met with very tall Asians near the beginning of the Amazon River, in the part that still belongs to Peru. The were very white and had thin black hair, just like the ... Chinese do. And that the Tupi Guarani language cuts the area of spoken Quechua in two, all the way from upriver Amazon down to the Atlantic. And that those indians that speak Tupi have very Chinese-looking eyes. By the way, the Chinese Shining Path movement of communism is Amazon Peruvian in origin.
Now, in modern times, how did Chinese influence ever get there, to the Amazon side of Peru? Especially 30 years ago or whatever, which is around when the Shining Path became active. (The communism in Cuba was from Russian origins)
We keep hearing of tunnels passing underneath the Pacific Ocean, even the Tibetans mentioned them to Ossendowski when he was escaping the Bolchevik revolution over Tibet.
And the Asians that Orellana came across were tall as are the humans that were born and raised in cavern worlds, shielded from the unrefined rays of The Sun. The Spaniards had camped for a few months beside an indian village, and apparently word got out to these Asians, and the Asians asked for and set up a four hour interview.
Boundries and proximity has to be defined by tunnel systems and the technology used to travel within them.
One thing is for sure, and laid out very nicely in the Gavin Menzes books; that the Chinese have been defining things in the Americas for a long time. And not just by sailboats/Chinese Junks.