Followup

Joshua asked about Lincoln's comment on slavery early in the Civil War.  Here is a passage from his letter to Horace Greeley on August 22, 1862:

I would save the Union. I would save it the shortest way under the Constitution. The sooner the national authority can be restored; the nearer the Union will be "the Union as it was." If there be those who would not save the Union, unless they could at the same time save slavery, I do not agree with them. If there be those who would not save the Union unless they could at the same timedestroy slavery, I do not agree with them. My paramount object in this struggle is to save the Union, and is not either to save or to destroy slavery. If I could save the Union without freeing any slave I would do it, and if I could save it by freeing all the slaves I would do it; and if I could save it by freeing some and leaving others alone I would also do that. What I do about slavery, and the colored race, I do because I believe it helps to save the Union; and what I forbear, I forbear because I do not believe it would help to save the Union. I shall do less whenever I shall believe what I am doing hurts the cause, and I shall do more whenever I shall believe doing more will help the cause. I shall try to correct errors when shown to be errors; and I shall adopt new views so fast as they shall appear to be true views.

His war aims would soon change with the Emancipation Proclamation.  He explained in his second State of the Union message:

Fellow-citizens, we cannot escape history. We of this Congress and this administration, will be remembered in spite of ourselves. No personal significance, or insignificance, can spare one or another of us. The fiery trial through which we pass, will light us down, in honor or dishonor, to the latest generation. We say we are for the Union. The world will not forget that we say this. We know how to save the Union. The world knows we do know how to save it. We -- even we here -- hold the power, and bear the responsibility. In giving freedom to the slave, we assure freedom to the free -- honorable alike in what we give, and what we preserve. We shall nobly save, or meanly lose, the last best hope of earth. Other means may succeed; this could not fail. The way is plain, peaceful, generous, just -- a way which, if followed, the world will forever applaud, and God must forever bless.