The U.S. Thanksgiving holiday, observed on the fourth Thursday of November, stems from a rich history of celebrations. The best known of these celebrations is the first harvest festival at Plymouth, MA, where in autumn 1621 colonists and Native Americans gathered for a three-day feast to offer thanks for a bountiful harvest. In 1863, Pres. Abraham Lincoln issued a Proclamation of Thanksgiving, marking the beginning of national recognition of an annual Thanksgiving holiday in the United States. The Thanksgiving stamp is part of the Holiday Celebrations Series.