After washing up on Plymouth Rock in December of 1620, the 102 passengers of the Mayflower set about the task of conquering North America in the name of Puritanism. Religious fanaticism not being sufficient protection against Cold and Hunger, 46 of the original sinners died in the first winter.
With only 56 of them left, they enlisted the help of the Wampanoag to learn what to eat and how to grow it. It is said that the Wampanoag Nation had been fairly devastated by a bacterial outbreak of leptospirosis in the year or so preceding the English refugees' arrival, allowing English ships like the Mayflower to land nearly unopposed at someone else's house.
The first Thanksgiving, allegedly held in the autumn of 1621, was a three-day festival to which around 90 Wampanoags were invited alongside 56 of England's Least Desirables to celebrate the fact that they had not ALL died during the previous winter.
Over the next twenty plus years, up to 20,000 English escapees began to show up in modern-day Massachusetts and Rhode Island. Political and religious malcontents back home, unhappy with Catholic-sympathizing King Charles and not wanting to integrate into their own homeland, these Puritans then began to squabble and fight among themselves - shipping out the Quakers and other splinter groups preaching tolerance.
By the time we arrived at Thanksgiving 2.0 (55 years later in 1676), the following proclamation was made by Edward Rawson, Clerk of the Governing Council of Charleston Massachusetts, before digging in:
"The Holy God having by a long and Continual Series of his Afflictive dispensations in and by the present Warr with the Heathen Natives of this land....
"The Council has thought meet to appoint and set apart the 29th day of this instant June, as a day of Solemn Thanksgiving and praise to God for such his Goodness and Favour, many Particulars of which mercy might be Instanced, but we doubt not those who are sensible of God's Afflictions...."
So, after half a century of afflictions (i.e., pesky native Wampanoags and disgruntled Puritans), the English invaders had something more to be thankful about again. This is a different dinner table from that of 1621 when they were so frighteningly outnumbered. Now there were thousands of English in Massachusetts and, packing muskets and other nifty tech from the old country, were able to push back the "Heathen Natives of this land".
As a note, there is much disagreement on the circumstances of the first thanksgiving and even as to whether it actually happened. But today, across the US and wherever Americans are settled, this is a day which remembers the pseudo-veracious story of the First Thanksgiving. The one before the cowering newbies had established dominion over the natives.
Thankful for surviving. Thankful for the bounty. And thankful for the backup that was on its way.