But few outsiders know that The Church of Christ, Scientist, is the only denomination in the United States that observes Thanksgiving as a religious holiday, one marked by church services, specially published Bible lessons, and personal healing testimonials.
Ceremonial recognition of the November holiday even eclipses that of Christ's birth for many Christian Scientists, who don't worship together on Christmas unless it falls on a Sunday.
It was Eddy who established the tradition of Christian Science Thanksgiving services. Her emphasis on gratitude began with a harrowing tumble on the ice back in 1866, in which she sustained life-threatening internal injuries. She drifted in and out of consciousness for three days and--according to Christian Science teachings--was cured only after turning to New Testament accounts of Jesus Christ's healings.
The woman who had long experimented with various yet ultimately wanting forms of alternative medicine finally discovered what she believed to be missing elsewhere: God.
That epiphany and her own recovery, coupled with Eddy's New England roots, explain why Thanksgiving resonated so profoundly with her, according to Virginia S. Harris, the elected leader of the First Church of Christ, Scientist.
"The Bible was very, very important to Mary Baker Eddy and, obviously, gratitude and thanksgiving are important threads throughout," said Harris, interviewed by phone recently from the Mother Church, as the denomination's Boston headquarters are known. "[They are] an important way for us to connect with the divine. It opens our expressions, our thoughts, away from self-centeredness."
Eddy emphasized prayer as "an acknowledgment of what God is" rather than simply an appeal for blessings and favors, says Stephen Gottschalk, author of "The Emergence of Christian Science in American Religious Life."
Nowhere is that focus clearer than in the first chapter of "Science and Health with Key to the Scriptures," the fundamental teachings of the church published by Eddy in 1875.
"Are we really grateful for the good already received?" Eddy asks. "Then we shall avail ourselves of the blessings we have, and thus be fitted to receive more. If we are ungrateful for Life, Truth, and Love, and yet return thanks to God for all blessings, we are insincere and incur the sharp censure our Master pronounces on hypocrites."
There's also a patriotic flavor, as church members read Thanksgiving proclamations issued either by their state governor or the president.
Wendy Forest, a full time Christian Science practitioner -- or healer -- has been observing Thanksgiving as a religious holiday for more than 20 years.
"Really, it seems so natural [to go to church]," said Forest, who lives in Mahopac, N.Y. "It's how we decide when the turkey goes in. It's part of the rhythm of the day."
Throughout the year, Christian Scientists attend Wednesday night church "meetings" to share stories of healings and other things for which they are grateful. While the Thanksgiving service is similar in format, it allows attendants to take stock of the previous year and not simply speak to the quotidian, Forest believes.
And the past year or two have been good ones for the First Church of Christ, Scientist, says Harris. "Science and Health" is enjoying record exposure, with 200,000 copies sold last year, she said--nearly four times higher than in 1996. She attributes the spurt to Americans' renewed interest in spirituality in recent years and, specifically, in faith and healing.
Still, other signs indicate that the denomination is not as strong as it once was. Where Christian Science boasted more than 10,000 church-certified practitioners at the end of World War II, that figure has dropped to about 2,600. The number of Reading Rooms--lending libraries of Eddy's and other works--is also down from 2,400 or so a few years ago to 2,000.
All of that matters little to Elaine Betschart of Sacramento, Cal. The retired school teacher says she is consciously grateful to God from the moment she begins her morning prayers and readings each day until she retires at night.
Even as her husband of 47 years was dying last year, Betschart says she found many reasons to give thanks: that he never suffered in pain, that friends and family stood by, and, she says, that God provided love and care.
"A lot of it was grim," she says. "Yet what held me up was this way of thinking, this way of prayer.. I firmly believe that attitude is everything."