Mitchel Cohen has written a very lengthy and troubling history of the Americas, to include our traditional Thanksgiving. Not being an historian, this blogger thinks it is unwise to make any conclusions on the validity of what is written in this piece.
There is obviously a strong bias toward collectivist and against capitalism coming from the author. How much this bias colors the narrative is open for discussion. However, this blogger was previously aware of, from several other sources, at least some of what he mentions. This much is certain: Historically, power + greed + Christianity = human evil at its worst.
This blogger chooses to take the concept of thanksgiving and celebrate it in his own way during this time of tradition for such celebration, regardless of its probably tainted history.