The Pilgrims were, of course, migrants seeking refuge from intolerance and threats, hardship and violence. It is the recollection of their experience that underpins the deeply rooted American values not just of welcoming the stranger but of respecting religious diversity.

As dissenters against the interwoven church and state of their native England, Pilgrims were hounded in their homeland. “Like others who refused to follow the Church of England’s teachings, some of them were harassed, fined or even sent to jail,” recall the historians of the Pilgrim experience. “When they felt they could no longer suffer these difficulties in England, they chose to flee to the Dutch Netherlands.”

In time, however, economic hardship and fear of war led them to undertake a perilous Atlantic voyage to North America.

President Obama picks up the story in his 2015 Thanksgiving Proclamation:

Upon arriving in Plymouth, at the culmination of months of testing travel that resulted in death and disease, the Pilgrims continued to face great challenges. An indigenous people, the Wampanoag, helped them adjust to their new home, teaching them critical survival techniques and important crop cultivation methods. After securing a bountiful harvest, the settlers and Wampanoag joined in fellowship for a shared dinner to celebrate powerful traditions that are still observed at Thanksgiving today: lifting one another up, enjoying time with those around us, and appreciating all that we have.

In a moment of ugly politics and harsh pronouncements—especially with regard to refugees from Syria but also toward migrants and immigrants from many lands—and a harsh disregard for religious and cultural diversity, the president gently reminds Americans of their own history and recognizes that “the inherent selflessness and common goodness of the American people endures.”

“In the same spirit of togetherness and thanksgiving that inspired the Pilgrims and the Wampanoag, we pay tribute to people of every background and belief who contribute in their own unique ways to our country’s story,” declares the president. “Each of us brings our own traditions, cultures and recipes to this quintessential American holiday—whether around dinner tables, in soup kitchens or at home cheering on our favorite sports teams—but we are all united in appreciation of the bounty of our nation. Let us express our gratitude by welcoming others to our celebrations and recognize those who volunteer today to ensure a dinner is possible for those who might have gone without. Together, we can secure our founding ideals as the birthright of all future generations of Americans.”

This regard for America’s diversity and its tradition of lifting one another up has been a constant in Obama’s annual proclamations. The president does not use his Thanksgiving pronouncements to make bold political statements—as Lyndon Johnson did 50 years ago with his referencing of the passage of the Voting Rights Act, establishment of Medicare and Medicaid and war on poverty: “In the past year we have added greatly to that national legacy. We have guaranteed the right to vote to all our citizens. We have pledged dignity to our elderly—even in sickness. We have added new dimensions to the education of our youth. We have broadened the horizons of opportunity for our poor. And all the while, we have enjoyed the greatest prosperity in history.” Nor does the current president get as specific as, for instance, Dwight Eisenhower did with his detailed endorsements of the United Nations and its programs.

But Obama still gets attacked for infusing his proclamations with “multicultural pieties.”

What the critics do not get is that Thanksgiving is a holiday for “multicultural pieties”—for embracing diversity, for sharing our prosperity, for recalling the history of welcoming the stranger. And for carrying those legacies forward.

Presidents of both parties, and of many ideological traditions, have long understood this. In 2001, George W. Bush’s Thanksgiving Proclamation noted, “As we recover from the terrible tragedies of September 11, Americans of every belief and heritage give thanks to God for the many blessings we enjoy as a free, faithful, and fair-minded land.” That was in keeping with the former president’s statements respecting religious diversity in general, his specific recognition in those difficult days of the contributions of Arab-Americans, and his declaration that “we respect the vibrant faith of Islam which inspires countless individuals to lead lives of honesty, integrity, and morality.”

Forty years ago, in another trying moment for the nation, President Gerald Ford proclaimed, “Let us join in giving thanks for our cultural pluralism. Let us celebrate our diversity and the great strengths that have come from sharing our traditions, our ideas, our resources, our hopes and our dreams. Let us be grateful that for 200 years our people have been dedicated to fulfilling the democratic ideal—dedicated to securing ‘liberty and justice for all.’” Ford’s sometimes rival, Ronald Reagan, would use one of his Thanksgiving Proclamations to celebrate the fact that “[p]eople from every race, culture, and creed on the face of the Earth now inhabit this land. Their presence illuminates the basic yearning for freedom, peace, and prosperity that has always been the spirit of the New World.”

Eighty years ago, in the midst of the Great Depression, and with the threat of fascism rising in Europe, President Franklin Roosevelt crafted perhaps the finest of the many presidential proclamations of Thanksgiving. FDR highlighted connections between Americans of differing backgrounds, as well as well as a global responsibility to “by example and practice help to bind the wounds of others.”

“In traversing a period of national stress our country has been knit together in a closer fellowship of mutual interest and common purpose. We can well be grateful that more and more of our people understand and seek the greater good of the greater number. We can be grateful that selfish purpose of personal gain, at our neighbor’s loss, less strongly asserts itself. We can be grateful that peace at home is strengthened by a growing willingness to common counsel. We can be grateful that our peace with other Nations continues through recognition of our own peaceful purpose,” wrote the 32nd president. “But in our appreciation of the blessings that Divine Providence has bestowed upon us in America, we shall not rejoice as the Pharisee rejoiced. War and strife still live in the world. Rather, must America by example and in practice help to bind the wounds of others, strive against disorder and aggression, encourage the lessening of distrust among peoples and advance peaceful trade and friendship.”

FDR would, as the years went on, add some “multicultural pieties” of his own. In his last Thanksgiving Proclamation, issued in November, 1944, Roosevelt wrote, “Let every man of every creed go to his own version of the Scriptures for a renewed and strengthening contact with those eternal truths and majestic principles which have inspired such measure of true greatness as this nation has achieved.”

It is surely true that presidents and citizens do not always rise to the challenges of our times. But our values, our best ideals, are constant. We are descended from migrants and refugees and immigrants—and from those who welcomed those migrants, refugees, and immigrants. This is who we are as Americans. And the best measures of our greatness are found in a history of respecting diversity as a source of strength, and in an inclination to “encourage the lessening of distrust among peoples.”