Thanksgiving traces its origins to the 1621 harvest feast shared by Plymouth colonists and the Wampanoag people, though this event is often viewed differently by Native American historians. The holiday was not a national one until President Abraham Lincoln proclaimed it in 1863 during the Civil War. Influenced by centuries of local traditions and campaigning by Sarah Josepha Hale, the holiday was formally established as a national one and later fixed by Congress to the fourth Thursday of November. Origins and evolution 1621 harvest feast: The event most commonly remembered as the "first Thanksgiving" was a three-day harvest festival shared by 52 English colonists and about 90 Wampanoag people in Plymouth, Massachusetts. Wampanoag perspective: Indigenous historians note that the relationship between the Wampanoag and colonists was complex, involving strategic alliances, and argue that the traditional "friendly feast" narrative overshadows the true history of oppression and conflict. Colonial and state observances: For over a century, Thanksgiving was celebrated through local and state proclamations, including one by President George Washington in 1789, but not as a national holiday. National holiday established: President Abraham Lincoln issued the first national Thanksgiving proclamation in 1863, during the Civil War, partly as a way to promote unity. Modern holiday: In 1941, Congress officially established that Thanksgiving would be celebrated on the fourth Thursday of November. Other key events Spanish thanksgiving: Some historians point to a 1565 feast between Spanish settlers and the native Timucuan people in Florida as a potential "first Thanksgiving" in North America. Campaign for a national holiday: Sarah Josepha Hale, editor of Godey's Lady's Book, led a 36-year campaign to establish an annual Thanksgiving holiday before Lincoln's 1863 proclamation. Lincoln's proclamation: Lincoln's proclamation set the date for the last Thursday in November. Holiday timing change: President Franklin D. Roosevelt moved the date in 1939, leading to confusion and two holidays being celebrated. Congress later passed a resolution to settle the matter and establish the fourth Thursday of November.