[sargon]

The Emancipation Proclamation only freed slaves in areas (states) rebelling against the Federal government. Slaves in slave states loyal to the Federal government remained in their status for example Delaware. (Yes Delaware was a slave state! Slave population in Delaware was something like 120 slaves.) It took the 13th amendment(Ratified 12/06/1865) to abolish slavery everywhere in the US.

I'm aware of this, but the number of slaves in the "unaffected" states was very small. Still, an interesting historical distinction. It would have made sense to go ahead and have it apply everywhere, one would think. I wonder if it was because the powers Lincoln was exercising by issuing the Emancipation Proclamation were powers appropriate only to use against States in active rebellion? If not, I wonder what the reasoning was for the distinction?

[rockrr]

I wonder if it was because the powers Lincoln was exercising by issuing the Emancipation Proclamation were powers appropriate only to use against States in active rebellion?

That's it exactly.

[Reily]

To sell it politically Lincoln used the EP as a means of decreasing the labor supply in the South. This was (At least it was thought it would!) to harm the Southern war effort by diminishing production in supply and labor for military engineering.