Repost: Happy Thanksgiving

Adelle August, circa 1954
Although there were other "thanksgivings" celebrated in North America by foreigners ( see alternative claims to the first Thanksgiving ) , the feast that took place in Plymouth in August of 1621 is the one our modern celebration is most closely aligned with. After arriving in Plymouth in 1620, the Pilgrims had endured hardships but had managed to survive, in a large part due to the help of Squanto, an Indian who taught the Pilgrims how to fish, grow corn, and farm the land. At the end of their first year, the Puritans held a "harvest feast" celebrating the fruits of their farming efforts. The feast honored Squanto and their friends, the Wampanoag Indians. The feast was followed by three days of "thanksgiving" celebrating their good fortune.
Banquet Turkey Dinner, 1963
Although Indians and Pilgrims joined together for a meal of thanksgiving in 1621, the Indians didn't fare so well at other thanksgiving observances. In 1641, a raid against the members of the Pequot tribe in Connecticut was very successful, and the churches declared a day of "thanksgiving" to celebrate. During this feast, the decapitated heads of Natives were kicked through the streets of Manhatten. Many towns in New England held thanksgiving days to celebrate victories over the Natives.

The images of pilgrims and Indians that define Thanksgiving for us today were not part of the national celebration until the 19th century. Before 1900, you didn't see picutres of Pilgrims sitting down to eat with Indians. There was so much violence out west that the idea of a harmonius celebration between the Indians and Pilgrims was too difficult for most people to imagine.

J.C. Leyendecker, 1928
In 1939, Franklin D. Roosevelt departed from tradition by declaring November 23, the next to the last Thursday that year, as Thanksgiving. All of Lincoln's successors had proclaimed Thanksgiving for the final Thursday in November. But in 1939, the National Dry Goods Association had requested Roosevelt move Thanksgiving back one week to allow for a longer Christmas season. This caused considerable controversy, with 23 states celebrating Thanksgiving on the 23rd, and 23 states waiting until the 30th. This Thanksgiving was called "Franksgiving" by many who considered Roosevelt's proclamation an outrage. In 1941, Roosevelt announced that the extending of the Christmas season had caused no increase in retail sales, and on November 26, 1941, he signed a bill that established the fourth Thursday in November as the national Thanksgiving holiday, which it has been ever since.
(text taken from Caffeine Destiny)