Thanksgiving holiday, as we know it today, was recommended to President Lincoln by Sarah Josepha Hale, a prominent magazine editor.  Her letters to Lincoln urged him to have the "day of our annual Thanksgiving made a National and fixed Union Festival."

According to an April 1, 1864 letter from one of President Lincoln's secretaries, John Nicolay, this document was written by Secretary of State William Seward, and the original was in his handwriting.  Recorded in his diary on October 3, Fellow Cabinet member Gideon Welles complimented Mr. Seward on his work.  A year later, the manuscript was sold to benefit Union troops and has since disappeared.

A Proclamation.

The year that is drawing towards its close has been filled with the blessings of fruitful fields and healthful skies.  To these bounties, which are so constantly enjoyed that we are prone to forget the source from which they come, others have been added which are of so extraordinary a nature that they cannot fail to penetrate and soften even the heart which is habitually insensible to the ever-watchful providence of Almighty God.  In the midst of a civil war of unequalled magnitude and severity, which has sometimes seemed to invite and provoke the aggression of foreign states, peace has been preserved with all nations, order has been maintained, the laws have been respected and obeyed, and harmony has prevailed everywhere except in the theatre of military conflict, while that theatre has been greatly contracted by the advancing armies and navies of the Union.  The needful diversion of wealth and strength from the fields of peaceful industry to the national defense has not arrested the plough, the shuttle, or the ship.  The axe has enlarged the borders of our settlements, and the mines, as well as of iron and coal as of the precious metals, have yielded even more abundantly than heretofore.  Population has steadily increased, notwithstanding the waste that has been made in the camp, the siege, and the battle-field; and the country, rejoicing in the consciousness of augmented strength and vigor, is permitted to expect a continuance of years, with large increase of freedom.

No human counsel hath devised, nor hath any mortal hand worked out these great things.  They are the gracious gifts of the Most High God, who, while dealing with us in anger for our sins, hath nevertheless remembered mercy.

It has seemed to me fit and proper that they should be reverently, solemnly, and gratefully acknowledged, as with one heart and voice, by the whole American people.  I do, therefore, invite my fellow-citizens in every part of the United States, and also those who are at sea, and those who are sojourning in foreign lands, to set apart and observe the last Thursday of November next as a day of thanksgiving and prayer to our beneficent Father who dwelleth in the heavens.  And I recommend to them that, while offering up the ascriptions justly due to Him for such singular deliverances and blessings, they do also, with humble penitence for our national perverseness and disobedience, commend to His tender care all those who have become widows, orphans, mourners, or sufferers in the lamentable civil strife in which we are unavoidably engaged, and fervently implore the interposition of the Almighty hand to heal the wounds of the nation, and to restore it, as soon as may be consistent with divine purposes, to the full enjoyment of peace, harmony, tranquility, and union.

In testimony whereof, I have hereunto set my hand, and caused the seal of the United States to be affixed.

Done at the city of Washington, this third day of October, in the year of our Lord one thousand eight hundred and sixty-three, and of the independence of the United States the eighty-eighth.

(signed) Abraham Lincoln.