Down the road at Plimouth Plantation they hold onto the belief that the first Thanksgiving in the United States happened in 1621 at their location:
The history of Thanksgiving goes much further back than Plymouth and 1621. In fact, people across the world from every culture have been celebrating and giving thanks for thousands of years. In this country, long before English colonists arrived, Native People celebrated many different days of thanksgiving. “Strawberry Thanksgiving” and “Green Corn Thanksgiving” are just two of kinds of celebrations for the Wampanoag and other Native People.
In 1621, the English colonists at Plymouth (some people call them “Pilgrims” today) had a three-day feast to celebrate their first harvest. More than 90 native Wampanoag People joined the 50 English colonists in the festivities. Historians dont know for sure why the Wampanoag joined the gathering or what activities went on for those three days. Form the one short paragraph that was written about the celebration at the time, we know that they ate, drank, and played games. Back in England, English people celebrated the harvest by feasting and playing games in much the same way.
The English did not call the 1621 event a “thanksgiving.” A day of “thanksgiving” was very different for the colonists. It was a day of prayer to thank God when something really good happened. The English actually had their first thanksgiving in the summer of 1623. On this day they gave thanks for the rain that ended a long drought.