Story time
Once upon a time...long long ago... haha jk
Well, when the pilgrims came to the new world, the winters were always a huge struggle for them, and it required lots of food stores gathered from the previous year. If the harvest was good, they got through the winter without many fatalities. If it was a bad harvest...then well...lots of people died. After the first (unsuccessful) attempt for a colony at Jamestown, there was another wave of settlers that landed at Plymouth, Virginia. The original Thanksgiving was a feast to give thanks for a good harvest, and went on for something like 3 days (that's my kind of dinner!!). They invited the natives, who brought food. The natives helped the pilgrims greatly by showing them how to plant corn, how to fish, and how to stay warm.
So in short, it was a huge potluck with the British settlers and the Indians. Yum yum.