We all have myths. Most of what's said here we know, but some of it's a bit exaggerated. Settlements "dotted" the N. American east coast, but only really in Florida (and perhaps a place in S. Georgia), with Roanoake no longer in existent to do much dotting. In other words, basically from Georgia to Nova Scotia there wasn't a single dot.
For example, Tisquantum's "Native" planting technique was otherwise unattested in the Americas. However, it was attested in a part of Europe where he'd been taken by a raiding party. But it sounds rather less impressive to say that Tisquantum saved the British settlers by teaching them Iberian planting techniques he'd culturally appropriated without apparent attribution.
Then there's the entire process by which Thanksgiving became accepted enough to be made into a holiday. Such things usually have a lot of threads, instead of a single event--and when the dust settles, the events aren't necessarily entirely as believed. Such is the power of a "myth" or "story" which many anthropologists say are what social and cultural identity's built around. Under that kind of an analysis, a lot of "academic advocacy" in the last 50 years has been geared to creating myths and stories to reaffirm a strong ethnic identity by some groups and to undermine the myths and stories that affirm any sort of pan-US ethnos. Much of this is subject to a lot of spin and forgetfulness. It's racist to fail to undermine certain myths; it's racist to undermine certain myths. Depends on the Cause.