"to recommend to the People of the United States a day of public thanks-giving and prayer to be observed by acknowledging with grateful hearts the many signal favors of Almighty God, especially by affording them an opportunity peaceably to establish a form of government for their safety and happiness."This presidential proclamation was published in The Massachusetts Centinel, Wednesday, October 14, 1789.
Between the Washington and Lincoln presidencies, there were relatively few similar presidential “General Thankfgiving” proclamations. In 1863, President Lincoln began what has been an annual tradition from then to present day. You can read the text of every similar presidential proclamation ever issued at the Pilgrim Hall Museum website.