when was the first thanksgiving celebration

The event most commonly called the “first Thanksgiving” took place in the autumn of 1621 at Plymouth, in present‑day Massachusetts, during a three‑day harvest celebration shared by the Pilgrims and the Wampanoag people.

Key facts in a nutshell

• The gathering happened after the Pilgrims’ first successful harvest in Plymouth Colony, sometime between late September and early November 1621.

• It was a three‑day feast that included roughly 50 English colonists and around 90 Wampanoag men led by Massasoit.

• At the time, it was understood mainly as a harvest celebration; it was only in the 1800s that this 1621 feast became widely labeled the “First Thanksgiving” in American popular memory.

Longer timeline context

• Earlier “thanksgiving” ceremonies by Europeans in North America predate 1621, including religious services and feasts in places like St. Augustine, Florida (1565) and Frobisher’s expedition in present‑day Canada (1578), which some historians also describe as thanksgiving observances.

• The idea of setting aside special days of thanks was already common in both Indigenous harvest traditions and European Christian practice long before it became a formal U.S. holiday.

• A national, recurring Thanksgiving in the United States was not proclaimed until 1863, when Abraham Lincoln called for an annual Thanksgiving Day in November; Congress later fixed it as the fourth Thursday in November in 1941.

TL;DR: If someone asks “When was the first Thanksgiving celebration?” in the familiar U.S. sense, the standard answer is: a three‑day harvest feast at Plymouth in the fall of 1621.