Thanksgiving Day in the United States originated as a harvest festival, and is celebrated on the 4th Thursday of November each year. According to Wikipedia: "The event that Americans commonly call the "First Thanksgiving" was celebrated by the Pilgrims after their first harvest in the New World in 1621. This feast lasted three days, and-as accounted by attendee Edward Winslow-it was attended by 90 Native Americans and 53 Pilgrims. The New England colonists were accustomed to regularly celebrating "thanksgivings"-days of prayer thanking God for blessings such as military victory or the end of a drought." You can learn more at https://en.wikipedia.org/wiki/Thanksgiving_(United_States).