President Franklin D. Roosevelt signs a bill officially establishing the fourth Thursday in November as Thanksgiving Day.
The tradition of celebrating the holiday on Thursday dates back to the early history of the Plymouth and Massachusetts Bay colonies, when post-harvest holidays were celebrated on the weekday regularly set aside as “Lecture Day,” a midweek church meeting where topical sermons were presented. A famous Thanksgiving observance occurred in the autumn of 1621, when Plymouth governor William Bradford invited local members of the Wampanoag tribe to join the Pilgrims in a festival held in gratitude for the bounty of the season.