Abraham Lincoln called for the annual November tradition
During the American Civil War, President Abraham Lincoln issued a proclamation in 1863 that is credited with starting the annual tradition of late November Thanksgiving proclamations.
Issued a few months after the Battle of Gettysburg, a turning point in the conflict that saw the Union score a major victory, the proclamation named various blessings even amid the war.
"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," declared the proclamation.
"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 Praise to our beneficent Father who dwelleth in the Heavens."