It has been nearly 400 years since the Pilgrims celebrated their first successful corn harvest in Plymouth, Massachusetts, by inviting the Native American tribes likely responsible for their survival to a feast that turned into a three-day festival.

Less than half of those who had crossed the Atlantic on the Mayflower had survived into 1621. Were it not for members of the Wampanoag and Pawtuxet tribes, who taught those early Americans how to farm, hunt and so much more, Thanksgiving as we know it may not exist.

The Pilgrims likely wouldn't have made it to 1622, or have started a tradition that endures to this day, were it not for their Indian brothers and sisters. So they really did have plenty of reason to give thanks, starting with their good fortune in having such benevolent hosts.

In many respects, all Americans owe a debt of gratitude to the Wampanoag and Pawtuxet tribes.

Thanksgiving also exists thanks to the efforts of the Continental Congress, which during the Revolutionary War proclaimed days of thanksgiving, and of George Washington, who in 1789 issued the nation's first Thanksgiving proclamation to celebrate victory over the British and the ratification of the Constitution.

The author of "Mary Had a Little Lamb," Sara Josepha Hale, deserves credit as well. In the late 1820s, Hale began what would become a 36-year campaign to establish Thanksgiving a national holiday. The magazine editor's willingness to write letters and editorials and pester elected officials finally paid off in 1863 when President Abraham Lincoln made Thanksgiving a holiday. Lincoln, no doubt still reeling from July's bloody battle at Gettysburg, Pennsylvania, took advantage of Thanksgiving to encourage Americans to call on God to heal the wounds of a nation torn apart by Civil War.

Thanksgiving as we now know it, of course, has changed quite a bit over the years. Though families across America still gather to share turkey, all the trimmings and fellowship, many Americans spend a good portion of the day either watching football or engaging in that greatest of American pastimes — shopping.

More and more retailers now get a jump on Black Friday, the official start of the Christmas shopping season, on Thanksgiving Day.

And though not all feel the need to shop on the holiday, nor even sanction such activity, it could be argued that shopping forces us all to acknowledge that we have been blessed beyond measure to live in this great country, where there is so much abundance.

Above all, Thanksgiving is about gratitude. It's a day to reflect on all we've been given, the blessings we've received, the bounty we all share in.

Rich or poor, young or old, male or female, each of us can find something to be thankful for. And someone to be thankful to.

God truly has "shed his grace" on each of us to live in a country where liberty, justice and equality still matter, where freedom still reigns.

America is not perfect, but it truly is a more perfect union than most. That's something for which we can all give thanks.

Editor's note: This editorial was originally published on Nov. 26, 2015.