Can’t be. The Native American peoples all lived in peace and harmony from sea to shining sea until the evil White Supremacist Europeans came along. /s
There is an out for the Woke.
Europeans besides the Vikings were here before Columbus.
One suggestion I’m aware of is that, given the hazards of fishing anywhere where Muslims raided, it may be possible that fishermen from what we now call the British Isles were frequenting the rich fisheries off of the north east.
If so they were treating it as a trade secret.
Completely ignoring all the Woke nonsense, this suggestion holds out the possibility that there had been a continuum of European presence that nevertheless never amounted to a discovery because it was kept on the sly. This also means suggested Scottish (Sinclair) expeditions didn’t happen in a vacuum.
Now with respect to fishermen I would suggest that there may be a way to demonstrate their presence. Shipping fish back would need them to be processed in some way, either salted and dried or pickled, so they’d still be edible ... well, at least by the standards of the day. That would mean some seasonal processing capacity on this side of the pond which was in a place where the locals might not stir up trouble or confiscate any built up infrastructure (note, I’m not assuming a colony but just an outpost), say an island off Nova Scotia or some such.