Thanksgiving, or Thanksgiving Day, is a holiday celebrated in the United States on the fourth Thursday in November. It has been celebrated as a federal holiday every year since 1863, when, during the Civil War, President Abraham Lincoln proclaimed a national day . celebrated on the last Thursday in November. Thanksgiving was also celebrated nationally in 1789, after a proclamation by George Washington. As a federal and public holiday in the U.S., Thanksgiving is one of the major holidays of the year. Together with Christmas and New Year, Thanksgiving is a part of the broader holiday season.

The event that Americans commonly call the "First Thanksgiving" was celebrated by the Pilgrims after their first harvest in the New World in 1621. This feast lasted three days, and it was attended by 90 Native Americans (as accounted by attendee Edward Winslow) and 53 Pilgrims. The New England colonists were accustomed to regularly celebrating "thanksgivings"—days of prayer thanking God for blessings such as military victory or the end of a drought.[