'4,) that the
sovereignty of California was in the United States, in virtue of the
Constitution, by which power had been given to Congress to dispose of
and make all needful rules and regulations respecting the territory or
other property belonging to the United States, with the power to admit
new States into the Union. That decision followed preceding ones,
there cited. The question was then presented, how it was possible for
the judicial mind to conceive that the United States Government,
created solely by the Constitution, could, by a lawful treaty, acquire
territory over which the acquiring power had no jurisdiction to hold
and govern it, by force of the instrument under whose authority the
country was acquired; and the foregoing was the conclusion of this
court on the proposition. What was there announced, was most
deliberately done, and with a purpose. The only question here is, as I
think, how far the power of Congress is limited.

As to the Northwest Territory, Virginia had the right to abolish
slavery there; and she did so agree in 1787, with the other States in
the Congress of the Confederation, by assenting to and adopting the
ordinance of 1787, for the government of the Northwest Territory. She
did this also by an act of her Legislature, passed afterwards, which
was a treaty in fact.

Before the new Constitution was adopted, she had as much right to
treat and agree as any European Government had. And, having excluded
slavery, the new Government was bound by that engagement by article
six of the new Constitution. This only meant that slavery should not
exist whilst the United States exercised the power of government, in
the Territorial form; for, when a new State came in, it might do so,
with or without slavery.

My opinion is, that Congress had no power, in face of the compact
between Virginia and the twelve other States, to _force_ slavery into
the Northwest Territory, because there, it was bound to that
"engagement," and could not break it.

In 1790, North Carolina ceded her western territory, now the State of
Tennessee, and stipulated that the inhabitants thereof should enjoy
all the privileges and advantages of the ordinance for governing the
territory north of the Ohio river, and that Congress should assume the
government, and accept the cession, under the express conditions
contained in the ordinance: _Provided_, "That no regulation made, or
to be made, by Congress, shall tend to emancipate slaves