The tradition of the Pilgrims’ first Thanksgiving is steeped in myth and legend. Few people realize that the Pilgrims did not celebrate Thanksgiving the next year, or any year thereafter, though some of their descendants later made a “Forefather’s Day” that usually occurred on December 21 or 22. Several Presidents, including George Washington, made one-time Thanksgiving holidays. In 1827, Mrs. Sarah Josepha Hale began lobbying several Presidents for the creation of Thanksgiving as a national holiday, but her lobbying was unsuccessful until 1863 when Abraham Lincoln finally made it a national holiday.
Today, our Thanksgiving is the fourth Thursday of November. This was set by President Franklin D. Roosevelt in 1939 (approved by Congress in 1941), who changed it from Abraham Lincoln’s designation as the last Thursday in November (which could occasionally end up being the fifth Thursday, and hence too close to Christmas for businesses). But the Pilgrims’ first Thanksgiving began at some unknown date between September 21 and November 9, most likely in very early October. The date of Thanksgiving was probably set by Lincoln to somewhat correlate with the anchoring of the Mayflower at Cape Cod, which occurred on November 21, 1620 (by our modern Gregorian calendar–it was November 11 to the Pilgrims who used the Julian calendar).