<human>:  When was the first Thanksgiving?
<bot>: The first Thanksgiving was celebrated in 1621 by the Pilgrims and the Wampanoag Indians. The Pilgrims were a group of religious separatists who had fled England to escape persecution for their beliefs. They landed in Plymouth, Massachusetts, in 1620 and were joined by the Wampanoag Indians in 1621. The Pilgrims and the Wampanoag Indians shared a meal together, and the Pilgrims gave the Wampanoag Indians gifts of corn, beans, and squash.