The annual festival of Thanksgiving grew out of one such remembrance by the Pilgrims in 1621 to multiple observances by the New England colonies. It became their habit to call for a day of fasting and prayer in the spring in preparation for the planting and a day of prayer and thanksgiving in the fall in gratitude for the harvest. As war darkened the land during the American Revolution, the Continental Congress issued eight separate national Thanksgiving Proclamations and an additional seven proclamations for times of national fasting and prayer. All of that culminated in the first national presidential Thanksgiving proclamation in 1789, when George Washington, responding to a Congressional request, declared, in part, “Whereas it is the duty of all nations to acknowledge the providence of Almighty God, to obey His will, to be grateful for His benefits, and to humbly implore His protection and favor…Now therefore, I do recommend and assign Thursday, the 26th day of November…that we may all unite to render unto Him our sincere and humble thanks for His kind care and protection.” What started out as the simple recognition of a few Godly pilgrims and their native American neighbors, eventually became a national holiday – our national holiday of praise to God.
[Information taken from “Celebrating Thanksgiving in America” by David Barton.]