What evidence from the text supports the idea that today's is an invitation tradition

In late 1863, Pres. Lincoln labeled that last Thursday in November as a national day of thanksgiving. Nonetheless, in 1939, after a request from the National Retail Dry Goods Association, Pres. Franklin Roosevelt imposed that the holiday should consistently be celebrated on the 4th Thursday of the month in order to extend the holiday shopping period by a week.

As most students in the U.S. learn, the event we consider the “first” Thanksgiving happened in Plymouth, Mass. in 1621 when the Pilgrims (who actually called themselves separatists and weren't referred to as Pilgrims until the 1870s) gathered with the local Wampanoag peoples to celebrate the fall harvest.

In 1621, the Plymouth colonists and Wampanoag Indians shared an autumn harvest feast that is acknowledged today as one of the first Thanksgiving celebrations in the colonies. For more than two centuries, days of thanksgiving were celebrated by individual colonies and states.

Thanksgiving Day is a national holiday celebrated on various dates in Canada, the United States, some of the Caribbean islands, and Liberia. ... Although Thanksgiving has historical roots in religious and cultural traditions, it has long been celebrated as a secular holiday as well.

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