In this photo made on Wednesday, Feb. 1, 2012 an American flag flies over Point State Park in Pittsburgh.

Having just emerged from a close and often bitter presidential campaign, the nation may be helped today by remembering the political nature of Thanksgiving. Don't worry, we mean that in a positive way that has nothing to do with negative ads or the differences between conservative and liberal thought. It has everything to do with freedom, liberty and the nation's collective well-being.

The Pilgrims had barely arrived on this continent when they signed the Mayflower Compact. Their concern was for the "general good of the colony," and for "just and equal laws." Much later, President George Washington started the modern Thanksgiving tradition with a proclamation that included thanks to God for, among other things, government.

Washington expressed sincere thanks "...for the peaceable and rational manner in which we have enabled to establish constitutions of government for our safety and happiness, and particularly the national one now lately instituted; for the civil and religious liberty with which we are blessed, and the means we have of acquiring and diffusing useful knowledge; and, in general, for the great and various favors which He has been pleased to confer upon us."

Notice that a man so instrumental in winning the Revolutionary War and establishing the new government took no personal credit for those things, nor did he ascribe any to the other men who helped craft those things. All these years later we remain a nation governed by the Constitution and its principles. Even those who believe those principles have been distorted must acknowledge the basic framework that continues to guide all political subdivisions and that protects basic freedoms and rights. Americans rightly honor the soldiers and veterans who have sacrificed so much to preserve the nation, but it is God who deserves the credit.

That has been the essence of this holiday from the beginning. Thanksgiving is an annual reminder that all human beings walk the same road, and that they need to rely on each other and God. It is a reminder that the nation's heritage draws its strength from gratitude and humility, not selfishness or greed.

Religious people always have understood this. In recent years, researchers have begun to understand it, as well. Recent gratitude studies have endeavored to measure the effects of a thankful heart. At UCDavis, researchers reached a number of conclusions of the health benefits and positive behaviors associated with thankful attitudes. Even patients with neuromuscular diseases saw remarkable progress from what was termed "a 21-day gratitude intervention." They had more energy, better moods, were more optimistic and felt a sense of being connected with others.

Some people may find it odd that those who seem to have good reason to complain would find therapy in instead offering thanks, but that's part of the nation's history, as well.

Few Thanksgiving proclamations are as poignant as the one President Abraham Lincoln issued during the darkest days of the Civil War. The blessing the people enjoyed, he said, were so many "that they cannot fail to penetrate and soften even the heart which is habitually insensible to the ever watchful providence of Almighty God."

Some people today might say he was delusional, or even insensitive. He was neither. A spirit of gratitude makes people reach out to help the less fortunate. It is a spirit of action, not smugness, and it is one of the nation's most treasured traditions and legacies.

Properly cultivated and observed, it will always preserve the nation's strength.