>>63169920Formally, it's the celebration of a treaty between a colony of settlers and an indigenous american tribe which saved the colonists from starvation over winter when many of their old world crops failed in the new world. The treaty was marked by a banquet and the holiday is meant to emulate that banquet.
The foods served are meant to reflect the new world crops that the tribe offered for the feast, many of which they would go on to teach the settlers how to cultivate. In practice, it's an autumn harvest festival like most cultures have, but its date and theming is meant to mark the occasion of that treaty and the fact that some american ancestors were brought low by their hubris and then rescued by the very people they threatened. Nominally, the holiday is marked by themed feasting and a sense of general gratitude and humility--marking these virtues as a key takeway from the event.
Historically, the treaty was a rare moment of peaceful new world contact and held for a relatively long time in comparison to other tribal agreements of the period, before the death of a tribal leader and ensuing succession crisis annulled the terms of the treaty and brought those settlers into conflict with the tribe that had saved them only a generation prior. As with most first contact stories, the eventual ending was tragic and involved there being far fewer native americans in the world. Recognizing that this story is rare exception in what was overall a very bloody century, and the grim irony that sparing the settlers brought about eventual extermination, is part of why the holiday and its meanings are sometimes controversial.
