Thanksgiving Day is a national holiday in the United States and is celebrated on the fourth Thursday of November (see below in the Thanksgiving Countdown how many days left before the next one!). In 1621, the Plymouth colonists and Wampanoag Native Americans shared an autumn harvest feast that is acknowledged today as one of the first Thanksgiving celebrations in the colonies. It wasn’t until 1863, in the midst of the Civil War, that President Abraham Lincoln proclaimed a national Thanksgiving Day to be held each November.