Beginning with George Washington in 1789, annual presidential proclamations had declared the last Thursday of November as the Thanksgiving date. However, in 1941, a United States Congressional declaration officially designated the fourth Thursday of November as the date of the Thanksgiving holiday

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The precise historical origin of the holiday is disputed. Although Americans commonly believe that the first Thanksgiving happened in 1621, at Plymouth Plantation, in Massachusetts, there is strong evidence for earlier celebrations in Canada (1578) and by Spanish explorers in Florida (1565).

In the United States, certain kinds of food are traditionally served at Thanksgiving meals. Firstly, baked or roasted turkey is usually the featured item on any Thanksgiving feast table (so much so that Thanksgiving is sometimes referred to as "Turkey Day"). Stuffing, mashed potatoes with gravy, sweet potatoes, cranberry sauce, sweet corn, other fall vegetables, and pumpkin pie are commonly associated with Thanksgiving dinner. All of these are actually native to the Americas or were introduced as a new food source to the Europeans when they arrived. Turkey may be an exception. In his book "Mayflower," Nathaniel Philbrick suggest that the Pilgrims might already have been familiar with turkey in England, even though the bird is native to the Americas. The Spaniards had brought domesticated turkeys back from Central America in the early 1600s, and the birds soon became popular fare all over Europe, including England, where turkey became a "fixture at English Christmases." ("Mayflower," Nathan Philbrick, Penguin Books 2006, pg. 118.)