As every school child knows, the American tradition of Thanksgiving as a day of prayer and feasting dates back to the Pilgrims. Yet the unbroken tradition of celebrating Thanksgiving on the 4th Thursday of November began in 1863 with Abraham Lincoln, at a moment in the Civil War when its outcome in emancipation had at last become clear and Union victory finally seemed probable. Lincoln used the occasion to remind war-weary Americans of disasters they had averted, such as famine due to untended fields, depopulation, or the attack of a foreign power eager to take advantage of the nation’s division. “No human counsel hath devised nor hath any mortal hand worked out these great things. They are the gracious gifts of the Most High God, who, while dealing with us in anger for our sins, hath nevertheless remembered mercy,” Lincoln wrote. In this line, and in the proclamation’s conclusion, Lincoln anticipated the message of his Second Inaugural Address. He asked God, on behalf of the American people, “to heal the wounds of the nation and to restore it as soon as may be consistent with the Divine purposes to the full enjoyment of peace, harmony, tranquility, and Union” (emphasis added). Americans should not feel entitled to a speedy end to the war, Lincoln was careful to note.

Later Thanksgiving proclamations seldom have reminded Americans of their sins; instead, they have marked milestones and successes, while invoking American ideals of liberty and human rights, often in language that, from the point of view of racial and religious minorities, seemed more aspirational than factual. Yet the words presidents have used to invoke these ideals are telling. A notable example is Truman’s first Thanksgiving proclamation, issued 75 years ago, two and a half months after the end of World War II. It invokes the unity of the nation throughout the just completed war, drawing a lesson that emphasizes the equality of all who fought, and of those who fought with those who led:

We give thanks with the humility of free men, each knowing it was the might of no one arm but of all together by which we were saved. Liberty knows no race, creed, or class in our country or in the world. In unity we found our first weapon, for without it, both here and abroad, we were doomed. None have known this better than our very gallant dead, none better than their comrade, Franklin Delano Roosevelt. Our thanksgiving has the humility of our deep mourning for them, our vast gratitude to them.

A year later, Truman would appoint a Commission on Civil Rights to conduct the first comprehensive federal review since Reconstruction of infringements on the rights of African Americans and other minority groups.