Remember what you were taught in grade school? Fleeing religious persecution, the Pilgrims sailed from England, landed on Plymouth rock over two months later, barely survived their first winter. With the help of Squanto and the friendly Wampanoag, who taught them how to exploit the local fish and game, plant corn and squash, and also protected them from other hostile tribes, the band of colonists succeeded in establishing a tenuous foothold at the edge of the North American wilderness. The first Thanksgiving in 1621 was held to celebrate a bountiful harvest with the tribe that helped make it possible.

The real story, it turns out, is neither as simple nor as consoling as this pared down history would suggest. Not that the historians agree on what the real Thanksgiving story is. And it isn't just historians who are squabbling over the significance of America's feast day. It is ordinary Americans like-- well-- Rush Limbaugh for example, who are weighing in on the events of four hundred years ago.

They did sit down and have free-range turkey and organic vegetables, Rush allows, "but it was not the Indians... it was capitalism and Scripture which saved the day." And it wasn't just a bitter winter and shortage of food that imperiled Pilgrim survival; it was, you guessed it, socialism, and those commune dwelling hippie Pilgrims themselves.

The popular talk radio host blames the Pilgrim's communal work ethic and equal sharing of the fruits of their labors for the colony's rocky first year in which half of the one hundred settlers perished of starvation and disease--

"The most creative and industrious people had no incentive to work any harder than anyone else, unless they could utilize the power of personal motivation!"

The tide turned, according to Rush, when the colony's governor, William Bradford, assigned a private plot of land to each family, thereby setting loose the beneficent powers of the marketplace in the People's Republic of Plymouth Rock.

This revisionist history is greeted with bemusement by professional historians. But Limbaugh is not alone in using Thanksgiving to score some political points. While Thanksgiving's enthusiasts view it as a celebration of the boldness, piety and sacrifices of the first European migrants to American shores, the holiday's critics claim that it whitewashes the genocide and ethnic cleansing of indigenous people.

If you happen to spend Thanksgiving in Plymouth Massachusetts this year, you can choose between two public commemorations. You can watch the official parade, in which townspeople dressed like pilgrims march to Plymouth Rock bearing blunderbusses and beating drums. Or you can stand on the top of Coles Hill with indigenous people and their supporters and fast in observance of what they call a "national day of mourning" in remembrance of the destruction of Indian culture and peoples.

These two events represent radically different visions of American history. The official version, the one we learn in school, essentially starts with the landing of the Mayflower in 1620 in a small bay north of Cape Cod. In the Native version, on the other hand, the appearance of the Pilgrims on American shores marks the beginning of the end.

In fact, the end times began for Massachusetts Indians several years earlier, when British slaving crews inadvertently introduced smallpox-- carried by their infected cattle-- to coastal New England killing over ninety percent of the local population, who lacked antibodies to fight the disease. (Compare this astonishing figure to the 30 percent death rates at the height of the Black Plague.)

While the decimated Wampanoag helped the British boat people survive their first harrowing year, Native Americans say that the favor was not returned. A group which calls itself "The United American Indians of New England" alleges that in return for Indian generosity, Pilgrims stole their grain stores and robbed Wampanoag graves .

The historical evidence for grave robbing is a bit thin. And perhaps we can forgive the starving Pilgrims for pilfering a little Indian corn. In any event, this petty thieving doubtless ended with their first ample harvest, which was celebrated with a three day feast. It remains an open question, however, whether the Wampanoag were actually invited, or if they crashed the party , as some historians now suggest, when they heard gunfire from the stockaded village and came to check out what the commotion was all about.

There is also the much debated question of what was on the menu . There is no evidence for turkey, it turns out, only some kind of wild fowl-- likely geese and duck-- venison, corn mush and stewed pumpkin, or traditional Wampanoag succotash. Cranberries, though native to the region, would have been too tart for desert, and sweet potatoes were not yet grown in North America, though grapes and melons would have been available.

The notion that the first Thanksgiving was some kind of cross-cultural love-fest, as it has been portrayed, is also disputed by historians, who say that the settlers and the Indians were brought together less by genuine friendship than by the extremity of their mutual need. The two struggling communities were never more than wary allies against other tribes.

The colonists were contemptuous of the Indians, who they regarded as uncivilized and satanic heathens, and the fragile early peace between Native Americans and the early settlers would soon unravel in a horrific manner in what is now Mystic Connecticut, where the Pequot tribe was celebrating their own Thanksgiving, the green corn festival. In the predawn hours, settlers-- not the Pilgrims, but a band of Puritans-- descended on their village and shot, clubbed and burned alive over 700 native men, woman and children.

This slaughter, according to Robert Jensen, a professor at the University of Texas at Austin, was the real origin of Thanksgiving -- so proclaimed in 1637 by Massachusetts Bay Governor John Winthrop in gratitude for God's destruction of the defenseless Pequot village. Thereafter massacres of the Indians were routinely followed by "days of thanksgiving."

Some blogosphere historians have gone so far as to claim that it was in order to consolidate this plethora of macabre feasts that George Washington made his Thanksgiving Day Proclamation in 1789. In reality, our first president's aim was not to celebrate the genocide against the Indians, but to pay tribute to the survival of the fledgling but still imperiled nation. Nevertheless, troubling questions about the origins of our national feast remain.

Jane Kamensky, a professor of history at Brandeis University, wondered on the website Common-Place (in 2001) whether it makes sense to stir up the historical pot, "to plumb the bottom of it all - to determine whether the first Thanksgiving was merely a pretext for bloodshed, enslavement, and displacement that would follow in later decades."

"To ask whether this is true is to ask the wrong question. Thanksgiving is true to its purposes," Kamensky writes , "And that's all it needs to be. For these holidays say much less about who we really were in some specific Then, than about who we want to be in an ever changing Now."

It seems odd for a historian to argue that history doesn't matter. A Thanksgiving which ignores the systematic destruction of Indian cultures which followed hot on the heels of the Plymouth feast not only does a disservice to indigenous peoples, it falsifies our understanding of ourselves and our history.

While few would suggest that Thanksgiving should become the occasion for a yearly guilt trip, we would do well to remember the price the first Americans paid for European expansion into their territories as we sit around the bountiful table with our family and friends. Only by openly acknowledging the sins of our collective past, is it possible to proceed toward a future that all Americans can feel thankful for.