The original harvest celebration of the Pilgrims happened in the autumn of 1621 to celebrate the colony's first successful year. President George Washington proclaimed the first national day of thanksgiving in 1789, but it was president Abraham Lincoln who officially declared the last Thursday in November Thanksgiving, beginning in 1863. It was during the Civil War, and Lincoln's proclamation advised people to make this holiday a special time for family, religion, and community. Much later, President Franklin Roosevelt moved Thanksgiving to the third Thursday of November to create a longer Christmas shopping season. But in 1941, Congress made Thanksgiving fall on the fourth Thursday in November, and it's been that way ever since!