Maybe it didn't free any slaves at that exact moment, but as United States forces pressed deeper into the rebelling states, it had the effect of freeing hundreds of thousands, if not millions. And just look up how the south screamed about it. Here's what Frederick Douglass had to say on the subject of the Emancipation Proclamation:
...and in the fullness of time, we saw Abraham Lincoln, after giving the slave-holders three months' grace in which to save their hateful slave system, penning the immortal paper, which, though special in its language, was general in its principles and effect, making slavery forever impossible in the United States. Though we waited long, we saw all this and more.As late as January 1865 Lincoln was still open to the idea of a compensated emancipation and offered 400 million dollars for that purpose at the Hampton Roads conference.Can any colored man, or any white man friendly to the freedom of all men, ever forget the night which followed the first day of January, 1863, when the world was to see if Abraham Lincoln would prove to be as good as his word? I shall never forget that memorable night, when in a distant city I waited and watched at a public meeting, with three thousand others not less anxious than myself, for the word of deliverance which we have heard read today. Nor shall I eve forget the outburst of joy and thanksgiving that rent the air when the lightning brought to us the emancipation proclamation.
The confederates should have taken his offer. The 13th amendment had finally passed the House of Representatives just a few days before, thanks to the recent elections finally giving the necessary supermajority to the Republicans.
Who were then pressed into contraband camps and put to work.