What important effects did the emancipation proclamation have on The Civil War of America?

The Emancipation Proclamation moved slavery front and center to the cause that the Union was rallying around. When the Civil War began things like "state's rights" and "slave states" as opposed to "free states" defined the cause. However, once Lincoln threw himself and the Union into eliminating slavery forever, the dynamics would have far reaching implications. Freed slaves could join units and fight for the Union vs. the Confederacy, freed slaves would await decisions about citizenship and rights that Lincoln never formalized prior to his asination. The Grand Old Party would squander the potential political support of freed slaves by failing to codify their freedom into citizenship that was equal to white citizenship in the South.