National holiday in the US (fourth Thursday in Nov) and Canada (second Monday in Oct), first celebrated by the Pilgrim settlers in Massachusetts after their first harvest 1621.
In the US it was proclaimed a national holiday 1863. Since 1942 it has been celebrated, by act of Congress, on the fourth Thursday in November. The original day of thanksgiving was proclaimed by Massachusetts governor William Bradford after the Pilgrims had survived their first winter, owing largely to help from their Indian ally Massasoit.
Fourth Thursday in November in the United States; second Monday in October in Canada; commemorates a feast held in 1621 by the Pilgrims and Wampanoag Indians; Also called: Thanksgiving Day.