Enlarge this image toggle caption James Reid Lambdin/Wikimedia Commons James Reid Lambdin/Wikimedia Commons Hale had already spent years campaigning for a national day of thanksgiving, using her platform as editor of one the country's most widely-read magazines and writing elected officials to argue that Americans urgently needed a national story. David Silverman, professor of history at George Washington University and author of This Land is Their Land, the Wampanoag Indians, Plymouth Colony, and the Troubled History of Thanksgiving.