The Plymouth settlers ("Pilgrims") set apart a holiday immediately after their first harvest in 1621. They held an autumn celebration of food, feasting, and praising God. The Governor of Plymouth invited Grand Sachem Massasoit and the Wampanoag people to join them in the feast. Evidence to support that claim came from diaries of Plymouth. National Thanksgiving Proclamations proclaim thanks for God’s providence in the events of the nation and, as President Washington explained in his Thanksgiving Proclamation, “for the many signal favors of Almighty God” in the lives of the people. As congress recognized the importance of Thanksgiving observance, President...