For most Americans, today is an important preliminary for this weekend, when they'll be shitting turkey out through their wholesome American guts. To some, though, it is the National Day of Mourning, an event founded when a Native American speaker was blocked from giving his Thanksgiving Day speech because it was insufficiently thankful.
The National Day of Mourning is an annual demonstration, held on the fourth Thursday in November, that aims to educate the public about Native Americans in the United States, notably the Wampanoag and other tribes of the Eastern United States; dispel myths surrounding the Thanksgiving story in the United States; and raise awareness toward historical and ongoing struggles facing Native American tribes. The first National Day of Mourning demonstration was held in 1970 after Frank "Wamsutta" James's speaking invitation was rescinded from a Massachusetts Thanksgiving Day celebration commemorating the 350th anniversary of the landing of the Mayflower. James instead delivered his speech on Cole's Hill in Plymouth, Massachusetts next to a statue of Ousamequin, where he described Native American perspectives on the Thanksgiving celebrations. The gathering became an annual event organized by the United American Indians of New England (UAINE) and coincides with both Thanksgiving Day in the United States and with Unthanksgiving Day, an annual ceremony held on Alcatraz Island in California.
More on the Wampanoag perspective.