On November 26, 1789, the first national Thanksgiving in America was celebrated. From the article:
"George Washington and Thanksgiving
Americans don’t know it and children aren’t taught it, but George Washington is responsible for our Thanksgiving holiday. It was our first president, not the Pilgrims and not Abraham Lincoln, who led the charge to make this day of thanks a truly national event.
On October 3, 1789, George Washington issued his Thanksgiving proclamation, designating for “the People of the United States a day of public thanks-giving” to be held on “Thursday the 26th day of November,” 1789, marking the first national celebration of a holiday that has become commonplace in today’s households.
While subsequent presidents failed to maintain this tradition, it was Washington’s original proclamation that guided Abraham Lincoln’s 1863 Thanksgiving Proclamation. In fact, Lincoln issued his proclamation on the same day, October 3, and marked the same Thanksgiving Day, Thursday, November 26, as Washington, setting Thanksgiving as the last Thursday of November after our first president’s example. The proclamation was printed in newspapers, including the October 9, 1789 issue of the Pennsylvania Packet and Daily Advertiser.
George Washington first mentioned the possibility of a national Thanksgiving Day in a confidential letter to James Madison in August 1789 (just months after taking office), asking for his advice on approaching the Senate for their opinion on “a day of thanksgiving.”
By the end of September 1789, a resolution had been introduced to the House of Representatives requesting that “a joint committee of both Houses be directed to wait upon the President of the United States, to request that he would recommend to the people of the United States a day of public thanksgiving.” The committee put the resolution before the president and George Washington issued the first national Thanksgiving Proclamation within days.
George Washington knew the value of a thanksgiving day long before becoming our first president.
During the Revolutionary War, he would order special thanksgiving services for his troops after successful battles, as well as publicly endorse efforts by the Continental Congress to proclaim days of thanks, usually in recognition of military victories and alliances."