attempts succeed? Why might not new Slave States be created outside the
Union, eventually to be drawn in? Why not? said the slave profiteer, and
gave money and assistance to the filibusters in Nicaragua. Why not? said
Lincoln, also. What protection against such an extension of boundaries?
Was the limitation of slave area to be on one side only, the Northern
side? And here at last, for Lincoln, was what appeared to be the true
issue of the moment. To dualize the Union, assuming its boundaries to be
fixed, was one thing. To dualize the Union in the face of a movement for
extension of boundaries was another. Hence it was now vital, as Lincoln
reasoned, to give slavery a fixed boundary on all sides. Silently, while
others fulminated, or rhapsodized, or wailed, he had moved inexorably to
a new position which was nothing but a logical development of the old.
The old position was--no extension of slave territory; the new position
was--no more Slave States.(2) Because Crittenden's Compromise left
it possible to have a new Slave State in Cuba, a new Slave State
in Nicaragua, perhaps a dozen such new States, Lincoln refused to
compromise.(3)

It was a terrible decision, carrying within it the possibility of civil
war. But Lincoln could not be moved. This was the first acquaintance
of the established political leaders with his inflexible side. In the
recesses of his own thoughts the decision had been reached. It was
useless to argue with him. Weed carried back his ultimatum. Seward
abandoned Crittenden's scheme. The only chance for compromise passed
away. The Southern leaders set about their plans for organizing a
Southern Confederacy.