The general question may be stated to be, whether the plaintiffs status, as a slave, was so
changed by his residence within that Territory, that he was not a slave in the State of Missouri, at
the time this action was brought.

In such cases, two inquires arise, which may be confounded, but should be kept distinct.

The first is, what was the law of the Territory into which the master and slave went,
respecting the relation between them?

The second is, whether the State of Missouri recognizes and allows the effect of that law
of the Territory, on the status of the slave, on his return within its jurisdiction.

[Curtis then conducted an extensive survey of Missouri Law, international law, and
several acts of Congress - including the Missouri Compromise. He concluded:]

First.

Second

Third.

Fourth.

Fifth.

The rules of international law respecting the emancipation of slaves, by the
rightful operation of the laws of another State or country upon the status of
the slave, while resident in such foreign State or country, are part of the
common law of Missouri, and have not been abrogated by any statute law
of that State.

The laws of the United States, constitutionally enacted, which operated
directly on and changed the status of a slave coming into the Territory of
Wisconsin with his master, who went thither to reside for an indefinite
length of time, in the performance of his duties as an officer of the United
States, had a rightful operation on the status of the slave, and it is in
conformity with the rules of international law that this change of status
should be recognized everywhere.

The laws of the United States, in operation in the Territory of Wisconsin at
the time of the plaintiffs residence there, did act directly on the status of
the plaintiff, and change his status to that of a free man.
The plaintiff and his wife were capable of contracting, and, with the
consent of Dr. Emerson, did contract a marriage in that Territory, valid
under its law; and the validity of this marriage cannot be questioned in
Missouri, save by showing that it was in fraud of the laws of that State, or
of some right derived from them; which cannot be shown in this case,
because the master consented to it.

That the consent of the master that his slave, residing in a country which
does not tolerate slavery, may enter into a lawful contract of marriage,
attended with the civil rights and duties which belong to that condition, is
an effectual act of emancipation. And the law does not enable Dr.
Emerson, or anyone claiming under him, to assert a title to the married
persons as slaves, and thus destroy the obligation of the contract of
marriage, and bastardize their issue, and reduce them to slavery.

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