The Emancipation Proclamation changed the course of the war, from protecting the Union to redefining freedom. But far from being the bringer of widespread freedom to all enslaved peoples, the Proclamation was very limited in its power.
The declaration promised that “…all persons held as slaves within any State or designated part of a State, the people whereof shall then be in rebellion against the United States, shall be then, thenceforward, and forever free…” This meant that only slaves in areas not occupied by the Union would be free and slaves in Union territory would remain enslaved. This provision was to ensure that the pro-slavery Border States would not leave the Union to maintain their property in slaves. It meant that in areas where the United States had power to end slavery they could not and in areas outside Union control slaves were declared free. At the end of the Proclamation, Lincoln outlined exactly which areas were in rebellion:
“Arkansas, Texas, Louisiana, (except the Parishes of St. Bernard, Plaquemines, Jefferson, St. John, St. Charles, St. James Ascension, Assumption, Terrebonne, Lafourche, St. Mary, St. Martin, and Orleans, including the City of New Orleans) Mississippi, Alabama, Florida, Georgia, South Carolina, North Carolina, and Virginia, (except the forty-eight counties designated as West Virginia, and also the counties of Berkley, Accomac, Northampton, Elizabeth City, York, Princess Ann, and Norfolk, including the cities of Norfolk and Portsmouth[)], and which excepted parts, are for the present, left precisely as if this proclamation were not issued.”
The exempted counties in Louisiana and Virginia were areas firmly under Union control, and thus outside the influence of the Proclamation.
In the moment, the Emancipation Proclamation freed very few slaves; it was the meaning and precedent that was important. News of the Proclamation spread into the South, giving slaves hope that the end of slavery was possible. It also gave them encouragement to take actions for their own freedom, for example enlisting in USCT regiments later in the war. In the long run, however, emancipation provided the precedent that led to the 13th, 14th, and 15th Amendments and the freedom of 4 million people at the end of the war. While limited at its issuance, it was truly a “new birth of freedom.”