In 1637 John Winthrop declared the first official Thanksgiving Day to give thanks for the slaughter of 700 Pequot Indians. On this #NationalDayofMourning I remember these and all other Native people who were victims and survivors of genocide. (see picture)
Thanksgiving proclamations were made mostly by church leaders in New England up until 1682, and then by both state and church leaders until after the American Revolution. During the revolutionary period, political influences affected the issuance of Thanksgiving proclamations. Various proclamations were made by royal governors, John Hancock, General George Washington, and the Continental Congress, each giving thanks to God for events favorable to their causes.
George Washington proclaimed the first nationwide thanksgiving celebration in America marking November 26, 1789, "as a day of public thanksgiving and prayer to be observed by acknowledging with grateful hearts the many and signal favours of Almighty God."
HOW DO NATIVE AMERICANS CELEBRATE THANKSGIVING? U.S. HOLIDAY A DAY OF MOURNING FOR INDIGENOUS PEOPLES
Native anti thanksgiving/anti Columbus day too
Puritans Days of humiliation and thanksgiving
A Youtube video on Anti-Thanksgiving: