Thanksgiving is a traditional North American holiday, which is a form of harvest festival. The initial "Thanksgiving" feast, held in 1621, was really a traditional English harvest celebration. The Pilgrims shared it with the Native Americans because they had taught the colonists to plant crops and hunt wild game.
The Pilgrims enjoyed a smorgasbord of Thanksgiving delights, including venison, duck, goose, clams, and dried fruit.
Without the Native Americans, the Pilgrims may not have survived the harsh winter and been able to celebrate their first harvest of plentiful crops in the New World. The colonists' first harvest feast lasted for three days. Today, Thanksgiving is celebrated on the fourth Thursday of November in the United States.