Thanksgiving has a long and, depending upon your source, varying history in the United States.

Virtually all of us are familiar with the story of the so-called first Thanksgiving, when the Pilgrims at Plymouth, Mass., gathered in 1621 for a communal thanksgiving observance, showing their gratitude for their harvest and safety in establishing a colony in the New World.

As early as 1607, according to some historical accounts, thanksgiving observances were already under way in the colony of Virginia, where Jamestown, and later other colonies, took root despite early days when it appeared the colony there would not survive.

Much earlier, in the 1570s, according to some accounts, thanksgiving festivities were held in what is now Canada, and later, during the American Revolution, the Continental Congress appointed a day annually to be set aside as a time of thanks.

What eventually became our present incarnation of the day began when President Abraham Lincoln declared the final Thursday of November 1863, as a day of thanksgiving.

What is interesting in all of these accounts is that community religious heads, political leaders, even somewhat spontaneous movements within a community, made these calls for thanksgiving not during times of great ease and comfort, but during times of difficulty. Most notably, in Virginia, the original Jamestown settlement there had lost nearly nine out of 10 settlers during its first three years. Lincoln made his declaration during the Civil War, a time when the nation literally teetered on the brink of collapse and more than 600,000 Americans — nearly 2 percent of the nation’s population — were dead or on their way toward being killed as a result of the conflict.

There seems to be something indomitable about the human spirit, or should we say the American spirit, that keeps the nation moving forward, pushing to do more, to become better, stronger. From those earliest settler days right on through the Civil War, two world wars, and now with a shaky economy and questionable political leadership, the nation keeps finding a way to move forward.

Part of that strength springs from the nation’s understanding that, despite the problems and challenges often facing us, people in America still have much to be grateful for.

So today, put aside political differences, overlook for a few hours the great challenges facing the nation, and be thankful for what we do have individually, as a community, and as a country.