Jay Parini, who teaches at Middlebury College, is the author of " The Way of Jesus: Living a Spiritual and Ethical Life ." The views expressed in this commentary are his own. View more opinion articles on CNN.

The editorial cartoonist shows us the great scene that precedes Thanksgiving as it unfolds. The Mayflower anchors in a cove near Plymouth Rock, and there's a small boat full of Pilgrims approaching the shore. Two Native Americans stand on the shore, and one of them says to the other: "Oh great! The *@#&* caravan is here!"

Funny, right? OK. But it's worth taking this seriously for a moment, as we gather around family tables for the yearly harvest festival that we call Thanksgiving.

To begin: Consider a classic text of our literature, the memoir "Of Plymouth Plantation," written by William Bradford, the first governor of the Plymouth Colony in Massachusetts. Bradford recalls how he and his fellow Pilgrims -- refugees who had undertaken a perilous journey to flee religious and political oppression in Europe -- arrived on the Mayflower ship in 1620.

Let's call this a kind of "migrant caravan."

Many of them survived that difficult first year on American soil -- though plenty didn't. They did this with considerable help from the Pokanoket tribe of Native Americans, which was led by a sympathetic chief called Massasoit.

The Pokanoket provided crucial survival skills as well as desperately needed supplies to the white settlers, and helped them get on their feet. Together Massasoit and Bradford forged a truce that lasted for half a century -- until all hell broke loose with King Philip's War. (But that is not a story for Thanksgiving.)

Bradford makes it clear that these white refugees from abroad were treated well by their hosts.

One of the other Pilgrims, Edward Winslow, wrote in detail about what must have been the first Thanksgiving on American soil in "Mourt's Relation," a memoir where he recalls a three-day harvest festival in 1621. There was a great store of wild turkeys consumed, and this is perhaps the basis for the tradition of eating turkeys at this meal.

Thanksgiving is a holiday that should, above any other holiday, remind us vividly of our history -- including the part that is personal: how we -- each of us -- wound up as Americans.

So many of us were refugees from oppression -- I count my family in this group. The native population welcomed us, and it's now in our DNA as a nation-state that we are that one place in the world where all people fleeing injustice and poverty and violence will, to the degree we can manage this, be given a warm welcome.

We've all benefited immeasurably from immigrants who have struggled to come to our shores. These are hard-working and well-intentioned people willing to give everything they have to honor a nation founded on the principle that "all men are created equal."

We are part of a grand experiment in world history. It would be a crying shame -- to say the least -- if, for whatever reason, we turned off our beacon to the world, refusing to welcome those in distress with open arms.

The foolish idea that our borders have been overrun by those seeking asylum because of "loopholes" in American immigration law is hokum of the first order : the worst sort of "fake news," and one that does considerable damage to our national sense of self.

Very recently we've seen an uptick in refugees from the "Northern Triangle" region of Central America, which includes Honduras, Guatemala and El Salvador. There are reasons for this increase that we should try to address. Most of those who fled Europe for North America in 1620 were, indeed, looking for better economic circumstances for their families -- in addition to religious freedom. And in fact, extreme poverty, as well as a fear of physical intimidation, abuse or worse, is what motivates many in the caravan -- and most asylum-seekers from Central America.

But in general, immigration over our southern border has been declining . Indeed, there have been more Mexicans leaving the United States than trying to come here in recent years.

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As we gather around our Thanksgiving table this year, let's give thanks for our ancestors, who were brave enough to cast off from their home shores -- willing to risk everything to make a fresh start on a faraway and unknown continent. And let's give thanks for the Native American tribes who welcomed them, who did not turn away our American caravan.