The U.S. government's Thanksgiving Proclamation creating a national holiday was written by the New York politician William Seward, not Abraham Lincoln. It was then issued under Lincoln's signature, and contains a number of outrageous lies and a bit of blasphemy.
The Proclamation praises "peace with all nations" while the authors of it were waging total war on their own nation.
It boasts that "order has been maintained" despite the reality of the New York City draft riots in which hundreds of New Yorkers were shot dead in the street by Lincoln's soldiers four months earlier.
It boasts that the laws have been respected and obeyed, but of course they were NOT by the author or signatory of the document, who had illegally suspended Habeas Corpus, imprisoned thousands of political dissenters, shut down hundreds of opposition newspapers, confiscated firearms, and committed treason by levying war upon the Southern states, as prohibited by Article 3, Section 3 of the U.S. Constitution.
The document further lies by calling the U.S. government's invasion of the Southern states and the waging of total war on the civilian population as "national DEFENSE."
The document blames God for the war, claiming that it was a result of His "anger for our sins."
Perhaps most outrageously, the Seward/Lincoln Thanksgiving Proclamation declares the "union" (a.k.a. the D.C.government) as a "Divine purpose."