Thanksgiving is celebrated on the fourth Thursday of November in the United States, which has a centuries-long history. The origins of the holiday are often linked to the 1621 feast shared between the Pilgrims and the Wampanoag people in Plymouth, Massachusetts. This three-day event marked a successful harvest and a spirit of cooperation, though it was not the formal “Thanksgiving” holiday recognized today.
When the Pilgrims arrived in today’s Massachusetts, many died during their first winter in the New World. Unprepared for the cold weather and sicknesses, surviving Pilgrims were helped by the Native Americans of the area; they were taught how to cultivate crops and fish and the differences between healthy and poisonous plants. About a year later, the Pilgrims successfully harvested their first crops. To celebrate this fortunate occasion, Native Americans and Pilgrims joined in a three-day feast of “thanksgiving,” which ultimately became the foundation for the modern holiday.
However, Thanksgiving was observed intermittently for much of the 17th and 18th centuries, often as a religious occasion to give thanks for harvests or other blessings. It was not a fixed annual event; different regions celebrated on various dates. In the 19th century, Sarah Josepha Hale, a prominent editor in “Godey’s Lady’s Book” magazine, campaigned for a national Thanksgiving holiday. Her efforts gained traction, especially during the Civil War.
In 1863, President Abraham Lincoln proclaimed Nov. 26 as a national day of “Thanksgiving and Praise,” hoping to unite the country during wartime. However, the date of the holiday was not standardized until 1941, when Franklin D. Roosevelt officially made the fourth Thursday of Nov. Thanksgiving.
Today, Thanksgiving is a time for family gatherings, feasts, and reflection. While it remains a day of gratitude for many, it is also a time of mourning for some Native Americans, who view the holiday as a reminder of colonization. Regardless of its different meanings, Thanksgiving continues to be a significant cultural observance in the U.S.

Sources: 

Thanksgiving Day | Meaning, History, & Facts | Britannica 

Thanksgiving 2024 ‑ Tradition, Origins & Meaning | HISTORY 

Thanksgiving: From Local Harvests to National Holiday | Smithsonian Institution