this Congress that accepted the cession from Virginia. They had
no power to accept it under the Articles of Confederation. But they
had an undoubted right, as independent sovereignties, to accept any
cession of territory for their common benefit, which all of them
assented to; and it is equally clear, that as their common property,
and having no superior to control them, they had the right to exercise
absolute dominion over it, subject only to the restrictions which
Virginia had imposed in her act of cession. There was, as we have
said, no Government of the United States then in existence with
special enumerated and limited powers. The territory belonged to
sovereignties, who, subject to the limitations above mentioned, had a
right to establish any form of government they pleased, by compact or
treaty among themselves, and to regulate rights of person and rights
of property in the territory, as they might deem proper. It was by a
Congress, representing the authority of these several and separate
sovereignties, and acting under their authority and command, (but not
from any authority derived from the Articles of Confederation,) that
the instrument usually called the ordinance of 1787 was adopted;
regulating in much detail the principles and the laws by which this
territory should be governed; and among other provisions, slavery is
prohibited in it. We do not question the power of the States, by
agreement among themselves, to pass this ordinance, nor its obligatory
force in the territory, while the confederation or league of the
States in their separate sovereign character continued to exist.

This was the state of things when the Constitution of the United
States was formed. The territory ceded by Virginia belonged to the
several confederated States as common property, and they had united in
establishing in it a system of government and jurisprudence, in order
to prepare it for admission as States, according to the terms of the
cession. They were about to dissolve this federative Union, and to
surrender a portion of their independent sovereignty to a new
Government, which, for certain purposes, would make the people of the
several States one people, and which was to be supreme and controlling
within its sphere of action throughout the United States; but this
Government was to be carefully limited in its powers, and to exercise
no authority beyond those expressly granted by the Constitution, or
necessarily to be implied f