When Lincoln declared the slaves in rebel hands “shall be, then, thenceforward, and forever free,” he had carefully exempted from his proclamation vast territories then under Union control. These included not only the four loyal border states—Missouri, Kentucky, Maryland, and Delaware—but also occupied areas of Tennessee, Louisiana, Florida, Virginia, and North Carolina. The London Spectator sneered that the only principle in the proclamation was that a man may not own another unless he is loyal to Lincoln’s government. But the Spectator then (and cynical Lincoln critics ever since) misunderstood the basis of Lincoln’s action. Because he was a constitutional leader and not a despot, Lincoln could only free the slaves as a war measure to suppress rebellion. The confiscation of enemy property during wartime is recognized as legitimate under the rules of war.

Thus, it is not true to say he freed the slaves where he had no power and left in bondage those over whom he exercised control. Lincoln had no constitutional authority to free the slaves in the loyal border states. And he knew he could not emancipate slaves in those areas where Union arms had quelled the rebellion. The practical effect of the Emancipation Proclamation was that the Union army became an army of liberation. Wherever it moved, thousands of slaves swarmed into its ranks, because the soldiers of the United States carried freedom in their haversacks.

Some British observers were more perceptive than the ruling aristocracy. Philosopher John Stuart Mill showed an acute understanding of what Lincoln had achieved:

The present government of the United States is not an Abolitionist government. Abolitionists, in America, mean those who do not keep within the constitution; who demand the destruction (as far as slavery is concerned) of as much of it as protects the internal legislation of each State from the control of Congress; who aim at abolishing slavery wherever it exists, by force if need be, but certainly by some other power than the constituted authorities of the Slave States. The Republican party neither aim nor profess to aim at this object. And when we consider the flood of wrath which would have been poured out against them if they did, by the very writers who now taunt them with not doing it, we shall be apt to think the taunt a little misplaced. But though not an Abolitionist party, they are a Free-soil party. If they have not taken arms against slavery, they have against its extension. And they know, as we may know if we please, that this amounts to the same thing. The day when slavery can no longer extend itself, is the day of its doom. The slave-owners know this, and it is the cause of their fury. They know, as all know who have attended to the subject, that confinement within existing limits is its death-warrant.

“I expect to maintain this contest until successful, or till I die, or am conquered, or my term expires, or Congress or the country forsakes me,” Lincoln had written at a time of discouragement. It must be admitted that Jefferson Davis was no less committed to fight on till the end. Lincoln’s task was greater. He had to win the war and to win the peace—for both North and South. Davis merely had to avoid losing.

Jefferson Davis reacted to the Emancipation Proclamation with predictable fury: it was, he told the Confederate Congress “the most execrable measure in the history of guilty man.” Lincoln wanted “to incite servile insurrection and light the fires of incendiarism,” charged Davis. He made this charge even though Lincoln had specifically urged freed slaves to engage in no violence—except in necessary self-defense. Frederick Douglass had written that the fear expressed by so many slaveholders “as to the danger of having their throats cut is because they deserve to have them cut.” Lincoln was becoming converted to the hard war theory that meant great destruction of rebel property. But he gave no support whatever to a slave uprising. The fact that there are no reported cases of murder or rape on Southern plantations speaks volumes of the character of Lincoln and the character of the freed slaves. The “wolf by the ears” so feared by Thomas Jefferson and hundreds of other Southern slaveholders for sixty years did not howl.