Lincoln’s views and feelings concerning slavery had not changed.  Those who conversed with him intimately upon the subject at that period know that he did not expect slavery long to survive the triumph of the Union, even if it were not immediately destroyed by the war.  In this he was right.  Had the Union armies achieved a decisive victory in an early period of the conflict, and had the seceded States been received back with slavery, the “slave power” would then have been a defeated power, defeated in an attempt to carry out its most effective threat.  It would have lost its prestige.  Its menaces would have been hollow sound, and ceased to make any one afraid.  It could no longer have hoped to expand, to maintain an equilibrium in any branch of Congress, and to control the government.  The victorious free States would have largely overbalanced it.  It would no longer have been able to withstand the onset of a hostile age.  It could no longer have ruled,—­and slavery had to rule in order to live.  It would have lingered for a while, but it would surely have been “in the course of ultimate extinction.”  A prolonged war precipitated the destruction of slavery; a short war might only have prolonged its death struggle.  Lincoln saw this clearly; but he saw also that, in a protracted death struggle, it might still have kept disloyal sentiments alive, bred distracting commotions, and caused great mischief to the country.  He therefore hoped that slavery would not survive the war.

But the question how he could rightfully employ his power to bring on its speedy destruction was to him not a question of mere sentiment.  He himself set forth his reasoning upon it, at a later period, in one of his inimitable letters.  “I am naturally antislavery,” said he.  “If slavery is not wrong, nothing is wrong.  I cannot remember the time when I did not so think and feel.  And yet I have never understood that the Presidency conferred upon me an unrestricted right to act upon that judgment and feeling.  It was in the oath I took that I would, to the best of my ability, preserve, protect, and defend the Constitution of the United States.  I could not take the office without taking the oath.  Nor was it my view that I might take an oath to get power, and break the oath in using that power.  I understood, too, that, in ordinary civil administration, this oath even forbade me practically to indulge my private abstract judgment on the moral question of slavery.  I did understand, however, also, that my oath imposed upon me the duty of preserving, to the best of my ability, by every indispensable means, that government, that nation, of which the Constitution was the organic law.  I could not feel that, to the best of my ability, I had even tied to preserve the Constitution—­if, to save slavery, or any minor matter, I should permit the wreck of government, country, and Constitution all together.”  In other words, if the salvation of the government, the Constitution, and the Union demanded the destruction of slavery, he felt it to be not only his right, but his sworn duty to destroy it.  Its destruction became a necessity of the war for the Union.