John Hancock (1737-1793), an American merchant and Revolutionary leader, was the president of the Provincial Congress of Massachusetts.  He became well known for having been the first member of the Continental Congress to sign the Declaration of Independence.

On April 15, 1775, the Provincial Congress of Massachusetts declared A Day of Public Humiliation, Fasting and Prayer, signed by the President of the Provincial Congress, John Hancock:

“In circumstances dark as these, it becomes us, as Men and Christians, to reflect that, whilst every prudent Measure should be taken to ward off the impending Judgements ....  All confidence must be withheld from the Means we use; and reposed only on that GOD who rules in the Armies of Heaven, and without whose Blessing the best human Counsels are but Foolishness - and all created Power Vanity;

“It is the Happiness of his Church that, when the Powers of Earth and Hell combine against it... that the Throne of Grace is of the easiest access - and its Appeal thither is graciously invited by the Father of Mercies, who has assured it, that when his Children ask Bread he will not give them a Stone ....

“RESOLVED, That it be, and hereby is recommended to the good People of this Colony of all Denominations, that THURSDAY the Eleventh Day of May next be set apart as a Day of Public Humiliation, Fasting and Prayer ... to confess the sins ... to implore the Forgiveness of all our Transgression ... and a blessing on he Husbandry, Manufactures, and other lawful Employments of this People; and especially that the union of the American Colonies in Defence of their Rights (for hitherto we desire to thank Almighty GOD) may be preserved and confirmed ....  And that AMERICA man soon behold a gracious Interposition of Heaven.

"By Order of the [Massachusetts] Provincial Congress, John Hancock, President." ¹

On November 8, 1783, Governor John Hancock, from Boston, Massachusetts, issued A Proclamation for a Day of Thanksgiving to celebrate the victorious conclusion of the Revolutionary War:

“John Hancock, Esquire

“Governor of the Commonwealth of Massachusetts

“A Proclamation for a Day of Thanksgiving:

“Whereas ... these United States are not only happily rescued from the Danger and Calamities to which they have been so long exposed, but their Freedom, Sovereignty and Independence ultimately acknowledged.

"And whereas ... the Interposition of Divine Providence in our Favor hath been most abundantly and most graciously manifested, and the Citizens of these United States have every Reason for Praise and Gratitude to the God of their salvation.

"Impressed therefore with an exalted Sense of the Blessings by which we are surrounded, and of our entire Dependence on that Almighty Being from whose Goodness and Bounty they are derived;

"I do by and with the Advice of the Council appoint Thursday the Eleventh Day of December next (the Day recommended by the Congress to all the States) to be religiously observed as a Day of Thanksgiving and Prayer, that all the People may then assemble to celebrate ... that he hath been pleased to continue to us the Light of the Blessed Gospel; ... That we also offer up fervent Supplications ... to cause pure Religion and Virtue to flourish ... and to fill the World with his glory." ²

¹ April 15, 1775, Massachusetts Provincial Congress declaring a Day of Public Humiliation, Fasting and Prayer.  Proclamation of John Hancock from Concord (from an original in the Evans collection, #14220, by the American Antiquarian Society.  David Barton, The Myth of Separation (Aledo, TX: Wall Builder Press, 1991), pp. 102-103.

² November 8, 1783, A Proclamation for a Day of Thanksgiving - signed by Governor John Hancock from Boston, Massachusetts.  From an original in the Evans collection, #18025, by the American Antiquarian Society.  David Barton, The Myth of Separation (Aledo, TX: WallBuilder Press, 1991), pp. 106-107.