George Washington issued the first presidential proclamation on October 3, 1789, recommending all Americans to set aside November 26 as a “Day of National Thanksgiving.” He and his successors through James Madison issued similar proclamations, but only sparingly and at various times of the year. From 1815 through 1860 there were no thanksgiving proclamations whatsoever.

By Samantha Strayer of The Federalist (A great republish from 2015)
Just as the status of a check-engine light speaks to the soundness of a vehicle, there are indicators throughout society that speak to the soundness of a nation. In a land as vast and populated as ours, with technological advancements once the sole province of science-fiction, it is nearly impossible to count such indicators.
But there is one — simple, short, and easy to read — that clearly reflects the spiritual health of the country: the annual Thanksgiving Day Proclamation.
First, a few clarifications are in order. Giving “thanks” is of course not unique to any particular group of people or geographic location, and expressions of gratitude can take many forms. What has become the American Thanksgiving holiday — aside from packed airports, creepy balloon parades, and political arguments — is really the amalgamation of several traditions: feasting in celebration of a bountiful harvest or military victory and submitting to God through supplication and praise.
Proclaiming a Day of Thanksgiving
George Washington issued the first presidential proclamation on October 3, 1789, recommending all Americans to set aside November 26 as a “Day of National Thanksgiving.” He and his successors through James Madison issued similar proclamations, but only sparingly and at various times of the year. From 1815 through 1860 there were no thanksgiving proclamations whatsoever.
Not until October 3, 1863, the very same day Washington had done 74 years earlier, did the annual tradition begin.
Abraham Lincoln, who venerated Washington and often followed his example, began issuing proclamations his first year in office. But not until October 3, 1863, the very same day Washington had done 74 years earlier, did the annual tradition begin.
Every president since has issued a Thanksgiving Day proclamation specifically set for the end of November. However, only the title, time of year, and — on a very superficial level — the theme of thankfulness has remained the same.
Indeed, no nation can withstand multiple large-scale wars, advancements in science and technology, and challenges to our understanding of human nature and remain unchanged. Whether mere hints or explicit proofs, you can trace national shifts in these proclamations. Most notable and notorious is the Progressive movement and its emphasis on human-generated moral and spiritual “uplift.”
Since Washington’s proclamation was the first of its kind (and President Obama references it in each of his), it is the legitimate standard by which we can and should assess the 2015 proclamation. Here are three notable differences.
1. In Service of God Versus Service to Others
Throughout his proclamation, Washington focuses on God and our relationship to him. Our duties are clear: “acknowledge His providence,” “obey His will,” “be grateful for His benefits,” “humbly implore His protection and favor,” and seek his “pardon for national and other transgressions.” In short, Thanksgiving should be “devoted by the people of these States to the service of that great and glorious Being who is the beneficent author of all the good that was, that is, or that will be.”
Washington explains that greater freedom for the individual and entire nation will naturally flow from this godly inclination. Of the 432 words comprising his proclamation, he refers to God 15 times.