There is a lot of information in the next several, several pages, so I will condense. One thing I forgot is Bradford didn't really highlight on their Thanksgiving Feast, but I can pinpoint when it happened. I will do my best at paraphrasing.
"All this while the Indians came skulking about them, and would sometimes sometimes show themselves aloof of, but when any approached near them, they would run away. And once they stole away their tools where they had been at work, and were gone to dinner. But about the 16 of March a certain Indian came boldly amongst them, and spoke to them in broken English, which they could well understand but marveled at it. At length they understood by discourse with him, that he was not of these parts, but belonged to the eastern parts, where some English ships came to fish with whom he was acquainted, and could name many of them by their names, amongst whom he had got his language. He became profitable unto them; as also of the people here, of their names, number, and strength; of their situation and distance from this place, and who was chief amongst them. His name was Samasetl he told them also of another Indian whose name was Squanto, a native of this place, who had been in England and could speak better English than himself. Being, after sometime of entertainment and gifts, dismissed awhile after he came again and ive more with him, and they brought again all the tools that were stolen away before. and made way for the coming of their great Sachem, called Massasoyet; who, about four or five days after, came with the chief of his friends and other attendance, with the aforesaid Squanto. With whom, after friendly entertainment and gifts given him, they made peace with him (which has now continued this 24 years)...
Next the Indians and Pilgrims made a 'peace' agreement to abide by, basically not to hurt each other, and what to do if someone did hurt the other.
"...The spring now approaching it pleased God the mortality began to cease amongst them, and the sick and lame recovered apace, which put as it were new life into them though they had born their sad affliction with much patience and contentedness...Afterwards they began to plant their corn, in which the service Squanto stood them in great stead, showing them both the mnner howt to set it and after how to dress and tend it. Also he told them except they got fish nd set with it (in these old grounds) it would come to nothing, and he showed them that in the middle of April they should have store enough come up the brook by which they began to build., and taught them how to take it, and where to get their provisions necessary for them; all which they found true by trial and experience."
"They began now to gather in the small harvest they had and to fit up their houses and dwellings against winter, being all well recovered in health and strength, and had all things in good plenty; for as some were thus employed in affairs abroad, others were exercised in fishing, about cod and bass, and other fish of which they took good store, of which every family had their portion. All the summer there was not want. And now began to come in store of fowl, as winter approached, of which this place did abound when they first came (but afterward decreased by degrees). And besides water fowl, there was great store of wild turkeys, of which they took many, besides venison etc. Besides they ahd about a peck a meal a week to a person or now since harvest, Indian corn to that proportion. "
So, I am thinking that after the harvest of corn, and the plentiful wild turkeys, this is where the harvest feast occurred, or Thanksgiving. What happened next was more ships with more people began to come in, and the people came with no provisions, thus they were very hungry that winter. After awhile, their commune idea fell apart- no one was prospering because they couldn't reap the fruit of their own labors, so they finally put a stop to that- for each man
Well, this will be all of the Thanksgiving history. There is much, much more written about the colony, which is rather boring :) Hope this helps shed some light on why we even celebrate what some people call ' Turkey Day'!