In his annual message to Congress, Lincoln identified the results of the recent election as the will of the people: that slavery should be abolished and a constitutional amendment be ratified to confirm it.

12/6/1864 ...It is the voice of the people now, for the first time, heard upon the question [of slavery]. In a great national crisis, like ours, unanimity of action among those seeking a common end is very desirable-almost indispensable. And yet no approach to such unanimity is attainable, unless some deference shall be paid to the will of the majority, simply because it is the will of the majority. In this case the common end is the maintenance of the Union; and, among the means to secure that end, such will, through the election, is most clearly declared in favor of such constitutional amendment...

In presenting the abandonment of armed resistance to the national authority on the part of the insurgents, as the only indispensable condition to ending the war on the part of the government, I retract nothing heretofore said as to slavery. I repeat the declaration made a year ago, the ‘while I remain in my present position I shall not attempt to retract or modify the emancipation proclamation, or by any of the Acts of Congress.' If the people should, by whatever mode or means, make it an Executive duty to re-enslave such person, another, and not I, must be their instrument to perform it...