Forget what you learned about the Thanksgiving holiday in the United States. It did not begin with the Pilgrims and Indians in 1621, when English settlers invited Native Americans to dinner. And Abraham Lincoln was not the first U.S. president to call for a national day of Thanksgiving. Instead, says historian Penny Colman, the origins of the holiday are more complex. They are rooted in ancient traditions, one woman’s activism, and political and business interests. Colman wrote the book “Thanksgiving: The True Story.” She explains that people around the world have held harvest festivals and days of thanksgiving for centuries. Usually leaders called for a day of thanksgiving after winning a battle or surviving a difficult time. In 1789, U.S. President George Washington called for a national day of thanksgiving during his first year in office. He did not say anything about Pilgrims and Indians. Instead, he urged Americans to thank God for their new government.