Many consider the real first Thanksgiving to be a celebration that took place more than twenty years after the Pilgrims honored Squanto and the Wampanoags at Plymouth rock. And this later feast didn't honor Native Americans at all -- it was a celebration of the murder of 700 unarmed men, women and children of the Pequot Tribe.
The story goes that by 1637, the first Pilgrims had been joined by many more British settlers who had come to America to enjoy the paradise of the new world. They took what land they wanted and enslaved or killed the Natives who got in their way. The Pequot Tribe, having refused to sign the earlier peace treaty Squanto had negotiated, fought back against the colonists and became their enemies.
One day, when the Pequot were gathered together for their annual "Green Corn Dance" in what is now known as Groton, Connecticut, they were surrounded and attacked by English and Dutch mercenaries. Forced to surrender, the Pequot were shot on sight as they emerged from the longhouse. Those who did not surrender, mostly women and children, were burned alive in the building.
The following day, the governor of the Massachusetts Bay Colony declared "a day of Thanksgiving" to celebrate and thank God for the victory over the Pequot. It was signed into law that, "This day forth shall be a day of celebration and thanksgiving for subduing the Pequots."
It is easy to see why we would choose to ignore that story in favor of the warm and fuzzy version we've learned in school. But if this version of history leaves you scratching your head, consider this: Others say the the real first Thanksgiving actually took place in 1565 in St. Augustine, Florida. But that's another story.