Here are two great quotes for the article:
In 1789, George Washington issued a proclamation calling for a day of "public thanksgiving and prayer" -- a day for Americans to acknowledge "the many signal favors of Almighty God, especially by affording them an opportunity peaceably to establish a form of government for their safety and happiness."
Lincoln acknowledged that the nation was "in the midst of a civil war of unequaled magnitude and severity." But he focused instead on the nation's blessings, urging his fellow Americans to remember that "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."