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 do it by freeing some and leaving others alone, I would do that. I have here stated my purpose according to my official duty, and I intend no modification of my oft-expressed personal wish that all men, everywhere, could be free.
Letter to Horace Greeley, 22 August 1862
