Rejoice always, pray without ceasing, in everything give THANKS, for this is the will of God in Christ Jesus for you. (1 Thessalonians 5:18)
Thanksgiving proclamation by George Washington is 1789:
“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 –humbly to implore His protection and favor . . .Now therefore, I, do recommend and assign Thursday, the twenty-sixth of November next, to be devoted by the people of these States to the service of that great and glorious Being, who is the Beneficent Author of all the good that was, that is, or that will be; that we may then all unite in rendering unto him our sincere and humble thanks for his care and protection of the people of this country.”
The proclamation, in full, is found here
