WHEN THE MAYFLOWER rounded the tip of Cape Cod and eased into what is now called Provincetown Harbor - after a sail of 98 days from Southampton - the Pilgrims looked ashore and wondered about two unknowns: What was the quality of the farmland and what was the nature of the natives? Only one of the Mayflower's passengers had been to the New World before, but he had been a troublesome fellow who had little to report about his ventures.

While wondering about the unknows, the Pilgrims paused to deal with a reality that everyone in the band surely did know: Their first responsibility must be to each other. In the final miles of their sea journey, the Pilgrims understood that they had crossed more than an ocean: they were traveling away from a political system, centuries old, that was based on privilege and blood. Even before giving thanks for the blessing of a safe journey, they paused to compose the Mayflower Compact, a liberal document for that time. It called for "just and equal laws . . . for ye general good of ye Colonie, unto which we promise all due submission and obedience."

With their own ranks in order, the Pilgrims, on the first sabbath in the New England of 1620, offered thanks for finally being free of old England. But the comforts of that freedom were mostly intellectual ones that did little to ease the fear of the wilderness. As Gov. William Bradford described it, in what may have been the first well-crafted English sentence to be written in the new land: "For summer being done, all things stand upon them with a weatherbeaten face; and the whole country, full of woods and thickets, represented a wild and savage view."

History has passed along the details of the first Thanksgiving, but two momentous events occurred before that day. If neither had happened, the Pilgrims might well not have survived. The first was the coming to the Plymouth community of Samoset, an Indian of friendly nature who offered the first assurance that guns would not be needed in future communications with the natives. Bradford found Samoset "free in speech, so far as he could express his mind, and of seemly carriage," but he also found him a source of invaluable information.

The second event was Samoset's introduction of Squanto, one of the most fascinating figures in early American history. The sole survivor of the Patuxet, a local Indian tribe that had been wiped out by a plague a few years before, Squanto had been captured years earlier by English explorers and sold into slavery in Spain. He escaped, went to England and returned to his native America. School children are told the story of Squanto's instructing the Pilgrims in the art of planting corn, somthing that the historians say is fact, not legend. In "Saints and Strangers," a clasic work of scholarship, George Willison writes that "from the day he met the Pilgrims [Squanto] never left them. Nothing could have been more fortunate. Without Squanto and his native skills and knowledge of the country, the Pilgrims would almost certainly have perlished or been forced to flee the plantation, for they would have had no crops. As it was, the gaunt specter of starvation haunted them day and night for years, and they just barely managed to pull through."

The first winter was the hardest, but with Squanto on hand to direct the spring planting, the food rations grew. It was not until that autumn - 1621 - that a holiday was ordered so that the community could, "after a more special manner, rejoice together." Whether "turkies" were eaten at the celebration isn't known, but the literature does suggest that the Indians and Pilgrims had considerably more than vegetarian tastes: Vension, duck and goose were the main meats, with "strong water" washing them down.

The feast became a yearly event, with Massasoit - known among the massachusetts, Cummaquid, Manomet and other tribes as "the Big Chief" - being one of the heartiest celebrants. Massasoit lived until the 1660s. The peace treaty between his tribes and the Pilgrims was never broken during those four decades, a remarkable achievement considering the violence that would one day mark relations between the red man and white man. Perhaps the treaty held for so long because each people was sensible enough not only to offer thanks to God for the harvest but also to sit across a table and delight in their own company. It is hard to start a war after a meal.