One could argue that there's no traditional American Thanksgiving dinner. While some families roast, deep-fry or barbecue their turkey, others opt for a vegetarian alternative such as Tofurky, or forego the turkey altogether. Each family has its own take on this all-American meal. For some, the traditional side dishes are cornbread, cranberries and candied yams. Others stick to stuffing, mashed potatoes and green beans. And of course, each year every gourmet magazine strives to spice up the menu with fresh spins on what it considers the old standbys. So the question is: Who put the turkey in Turkey Day, and just how traditional is this "American tradition"?

You probably can answer the first part of the question without hesitation: the Pilgrims, of course! In 1621, the Plymouth colonists and Wampanoag Indians shared a feast, which we now regard as the first Thanksgiving meal. From first-hand accounts of the feast, historians can prove that the Pilgrims and Wampanoags ate turkey and venison. But modern Thanksgiving staples such as pumpkin pie, cranberry sauce, corn on the cob and potatoes were not on the menu. Pilgrims didn't have access to sugar and potatoes in those days, and they kept corn dried in the fall. Among the dishes they could have eaten are Dutch cheese, wild grapes, lobster, cod and stewed pumpkin. The side dishes probably didn't matter much to the Pilgrims, though. They didn't eat a lot of vegetables and preferred meals comprised of several meats—which means that turkey probably wasn't the focus of their Thanksgiving meal, as it is for many families today.

Seventeenth-century table manners would seem foreign at our modern family feasts. Pilgrims didn't use forks, and they wiped their hands on large cloth napkins, which they also used to pick up hot food. They set every dish on the table at once and placed the best foods next to the most important people. Rather than pass dishes, they ate what was closest to them (forget sampling the lobster if it was across the table). Today, many families eat Thanksgiving dinner early in the afternoon. This tradition might spring from the Pilgrims' custom of eating the biggest meal of the day at noon. But while modern Thanksgiving meals emphasize family togetherness, in the Pilgrims' day, adults sat down to eat while the children and servants waited on them.

How did modern Thanksgiving celebrations evolve from the 1621 feast? The event now regarded as the first Thanksgiving wasn't a true thanksgiving in the Pilgrims' eyes, but rather a secular celebration of the season's harvest. To the Pilgrims, a day of thanksgiving was one in which they gathered—usually in a church—to thank God for his mercies. So the three days of dancing, singing and playing games known as the first Thanksgiving were more of a fall festival, occurring sometime between Sept. 21 and Nov. 11.

And to historians' knowledge, it was never repeated. New Englanders declared days of prayer and thanks years later—Nov. 30, 1777, the Continental Congress recommended a day of thanksgiving after US victory in the Battle of Saratoga. But these were days of religious observance. And while Presidents Washington, Adams and Madison declared days of thanksgiving during their terms, the practice was not an annual tradition. In fact, Presidents Jefferson and John Quincy Adams considered it an infringement on the separation of church and state.

Until Mourt's Relation, a colonial publication that contained Edward Winslow's first-hand account of the 1621 celebration, was rediscovered in the 1820s, Americans had forgotten the now famous feast. Along with the 1856 publication of Puritan William Bradford's manuscript "Of Plimoth Plantation,"which also mentions the celebration, this discovery sparked a newfound interest in the Pilgrims. This is when Americans began to associate their thanksgivings with the Plymouth colonists.

In 1863, magazine editor Sarah Hale wrote a letter to President Lincoln urging him to establish a national day of thanksgiving in order to unite the country. Until this point, the New England states had declared their own annual thanksgivings, which had become more secular and family-and-food focused. New Englanders had also introduced the holiday to other parts of the country. By the mid-1800s, even the southern states, which had rejected the Yankee custom, began to celebrate their own thanksgivings. Taking Hale's advice, President Lincoln declared the last Thursday in November, 1863, a national thanksgiving holiday.

At the turn of the century, the holiday gained popularity as immigrants, trying to assimilate to their new home's customs, added turkey to their ethnic cuisine. But it didn't become an official national holiday until 1941. In 1939, President Franklin D. Roosevelt broke with tradition by declaring the next-to-last Thursday of November Thanksgiving Day—after the National Retail Dry Goods Association's request to extend the Christmas shopping season by one week. His decision met with confusion. Twenty-three states observed the holiday on Nov. 23 and 23 states celebrated on Nov. 30; Texas and Colorado declared both days holidays. Thanksgiving football games had to be rescheduled, and no one knew when to serve the holiday meal. In 1941, President Roosevelt admitted his mistake and signed a bill that established the fourth Thursday in November as Thanksgiving Day, which it has been ever since.

Today, Thanksgiving truly is an American tradition—though its roots might not stretch as deep as legend tells us. While menus vary by region and household, it's a day when we come together as a nation to appreciate family and friendship. Just as the Pilgrims and Wampanoags did almost four centuries ago.