Yeah, I know that it really irritates the Lincoln veneration society to quote his letter to Greeley.
What it shows is that Frederick Douglass was correct in what he said in his memorial to Lincoln, which is that Preserving The Union was Lincoln’s goal in waging war on the States that wanted to leave the Union.
Lincoln was not going to sit idly by and let that happen any more than King George III was going to let the American colonies leave.
George’s government even outdid Lincoln by issuing two emancipation proclamations, Dunmore in 1775 and Philipsburg in 1779.