In 1863, President Abraham Lincoln designated the last Thursday in November as a national day of thanksgiving. However, in 1939, after a request from the National Retail Dry Goods Association, President Franklin Roosevelt decreed that the holiday should always be celebrated on the fourth Thursday of the month (and never the occasional fifth, as occurred in 1939) in order to extend the holiday shopping season by a week. The decision sparked great controversy, and was still unresolved two years later, when the House of Representatives passed a resolution making the last Thursday in November a legal national holiday. The Senate amended the resolution, setting the date as the fourth Thursday, and the House eventually agreed.

George Washington, John Adams and James Madison all issued proclamations urging Americans to observe days of thanksgiving, both for general good fortune and for particularly momentous events (the adoption of the U.S. Constitution, in Washington's case; the end of the War of 1812, in Madison's).

In a letter to his daughter sent in 1784, Benjamin Franklin suggested that the wild turkey would be a more appropriate national symbol for the newly independent United States than the bald eagle (which had earlier been chosen by the Continental Congress). He argued that the turkey was "a much more respectable Bird," "a true original Native of America," and "though a little vain & silly, a Bird of Courage."

Domesticated turkeys (the type eaten on Thanksgiving) cannot fly, and their pace is limited to a slow walk. Female domestic turkeys, which are typically smaller and lighter than males, can move somewhat faster. Wild turkeys, on the other hand, are much smaller and more agile. They can reach speeds of up to 20-25 miles per hour on the ground and fly for short distances at speeds approaching 55 miles per hour. They also have better eyesight and hearing than their domestic counterparts.

Turkey does contain the essential amino acid tryptophan, which is a natural sedative, but so do a lot of other foods, including chicken, beef, pork, beans and cheese. Though many people believe turkey's tryptophan content is what makes many people feel sleepy after a big Thanksgiving meal, it is more likely the combination of fats and carbohydrates most people eat with the turkey, as well as the large amount of food (not to mention alcohol, in some cases) consumed, that makes most people feel like following their meal up with a nap.

The turkey trot, modeled on that bird's characteristic short, jerky steps, was one of a number of popular dance styles that emerged during the late 19th and early 20th century in the United States. The two-step, a simple dance that required little to no instruction, was quickly followed by such dances as the one-step, the turkey trot, the fox trot and the bunny hug, which could all be performed to the ragtime and jazz music popular at the time. The popularity of such dances spread like wildfire, helped along by the teachings and performances of exhibition dancers like the famous husband-and-wife team Vernon and Irene Castle.