On the other hand, Lincoln had advocated passage of the 13th amendment, insisting that it be included in the 1864 Republican platform. After it had passed congress, he'd signed it and sent it to the states. So his position pushing for total abolition is well established at the time of his death.
By the time of Lincoln's death, the plantations had been laid waste, the slaves scattered, Lincoln's hold on the reins had slackened and change was on the wind.
Thomas Nast depicted the surrender in Harper's Weekly this way; I don't see Lincoln in the picture.