North consented to this provision, not because they considered it right
in itself, but because they were compensated--paid for it.

They at the same time got California into the Union as a free State. This
was far the best part of all they had struggled for by the Wilmot
Proviso. They also got the area of slavery somewhat narrowed in the
settlement of the boundary of Texas. Also they got the slave trade
abolished in the District of Columbia.

For all these desirable objects the North could afford to yield
something; and they did yield to the South the Utah and New Mexico
provision. I do not mean that the whole North, or even a majority,
yielded, when the law passed; but enough yielded--when added to the vote
of the South, to carry the measure. Nor can it be pretended that the
principle of this arrangement requires us to permit the same provision to
be applied to Nebraska, without any equivalent at all. Give us another
free State; press the boundary of Texas still farther back; give us
another step toward the destruction of slavery in the District, and you
present us a similar case. But ask us not to repeat, for nothing, what
you paid for in the first instance. If you wish the thing again, pay
again. That is the principle of the compromises of '50, if, indeed, they
had any principles beyond their specific terms--it was the system of
equivalents.

Again, if Congress, at that time, intended that all future Territories
should, when admitted as States, come in with or without slavery at their
own option, why did it not say so? With such a universal provision, all
know the bills could not have passed. Did they, then--could
they-establish a principle contrary to their own intention? Still
further, if they intended to establish the principle that, whenever