esided. And that, before the commencement of
this suit, they were sold by the Doctor to Sandford, the defendant,
who has claimed and held them as slaves ever since.

The agreed case also states that the plaintiff brought a suit for his
freedom, in the Circuit Court of the State of Missouri, on which a
judgment was rendered in his favor; but that, on a writ of error from
the Supreme Court of the State, the judgment of the court below was
reversed, and the cause remanded to the circuit for a new trial.

On closing the testimony in the court below, the counsel for the
plaintiff prayed the court to instruct the jury, upon the agreed state
of facts, that they ought to find for the plaintiff; when the court
refused, and instructed them that, upon the facts, the law was with
the defendant.

With respect to the plea in abatement, which went to the citizenship
of the plaintiff, and his competency to bring a suit in the Federal
courts, the common-law rule of pleading is, that upon a judgment
against the plea on demurrer, and that the defendant answer over, and
the defendant submits to the judgment, and pleads over to the merits,
the plea in abatement is deemed to be waived, and is not afterwards to
be regarded as a part of the record in deciding upon the rights of the
parties. There is some question, however, whether this rule of
pleading applies to the peculiar system and jurisdiction of the
Federal courts. As, in these courts, if the facts appearing on the
record show that the Circuit Court had no jurisdiction, its judgment
will be reversed in the appellate court for that cause, and the case
remanded with directions to be dismissed.

In the view we have taken of the case, it will not be necessary to
pass upon this question, and we shall therefore proceed at once to an
examination of the case upon its merits. The question upon the merits,
in general terms, is, whether or not the removal of the plaintiff, who
was a slave, with his master, from the State of Missouri to the State
of Illinois, with a view to a temporary residence, and after such
residence and return to the slave State, such residence in the free
State works an emancipation.

As appears from an agreed statement of facts, this question has been
before the highest court of the State of Missouri, and a judgment
rendered that this residence in the free State has no such effect;
but, on the contrary, that his original condition continued unchanged.

The court below