Much of what we know about the first Thanksgiving comes from a letter written by Edward Winslow in 1621. The letter, lost for nearly 200 years, was discovered by Boston publisher Alexander Young and later published in 1841.

The first Thanksgiving, according to the account, was primarily a day of fasting to remember and thank God.

While George Washington held a Thanksgiving as president, it was Abraham Lincoln that made it a national holiday.

Right after the battle of Gettysburg, Lincoln declared Thanksgiving an annual day of remembrance to be observed the fourth Thursday of every November. From 1863 to 1939, Thanksgiving took place on the fourth Thursday, allowing people to stop and to give thanks to God.

As Glenn outlined on radio, the tie between Thanksgiving and God slowly unraveled during the Progressive Era.

In an official statement issued by Theodore Roosevelt, a subtle change in wording and tradition began the unraveling.

"I, Theodore Roosevelt, president of the United States do hereby designate as a day of general thanksgiving, Thursday the 28th, this present November, and I recommend that throughout the land, people cease from their wanted occupations."

"Notice the date was still the same [the fourth Thursday of November], but this is the first time the president said we should take the day off," Glenn explained. "This was unusual because up until the Progressive Era, we thought it was abhorrent to take even Christmas off. ...In fact, the Pilgrims and our Founders thought it would be crass to take the day off and make it not a day of work for either holiday, either Thanksgiving or Christmas. We worked on Christmas. But it was the progressives that wanted us to cease from occupations."

Roosevelt's statement went on to "thank the giver of all good for the countless blessings in our national life." Glenn pointed out the subtle --- but important --- choice of words. The president used the word "national" rather than "individual."

Woodrow Wilson issued a similar statement, urging citizens to take the day off.

"I, Woodrow Wilson, president of the United States, do hereby designate Thursday the 27th of November as a day of Thanksgiving and prayer and invite the people throughout the land to cease from their wanted occupations."

At the beginning of the Depression in 1931, Herbert Hoover followed suit.

"I, therefore, Herbert Hoover, president of the United States, do hereby designate Thursday, November 26th, as the national day of Thanksgiving and recommend that our people rest from their daily labors, and in their homes and accustomed places of worship, give devout thanks for the blessings which a merciful Father have bestowed on all of us."

Again, while most people wanted to work, a progressive president told them to stay home and rest.

The most dramatic change happened in 1939 under Franklin Roosevelt.

"At the tail end of the Depression, Franklin Roosevelt, hoping to boost the economy by providing shoppers and merchants a few extra days to conduct their business between Thanksgiving and Christmas, moved Thanksgiving to November's third Thursday," explained Glenn. "So the only reason why we changed from the fourth Thursday to the third, was because in the third term of FDR, he officially disconnected it from God and connected it to the God of America, the almighty dollar."

The decision was not well received.

A Gallup poll at the time showed 59 percent of Americans disapproved of the date change. Twenty-two states decided to go along with Roosevelt's plan. Twenty-three decided to stick with the old date, affirming Thanksgiving should be about thanking God, not shopping. Both dates were recognized by the press, the latter referred to as the Republican Thanksgiving because it was connected to God, the founding and Abraham Lincoln.

In 1941, the Wall Street Journal looked at a large pool of data and declared the move a bust. It provided no real boost to retail sales. Unfortunately, what it did do was further separate the American people and society from God.

Just two years later, Roosevelt reversed his controversial decision, moving Thanksgiving back to the fourth Thursday in November.

Watch a segment from the program below: