ties? And

2. If it had jurisdiction, is the judgment it has given erroneous or
not?

The plaintiff in error, who was also the plaintiff in the court below,
was, with his wife and children, held as slaves by the defendant, in
the State of Missouri; and he brought this action in the Circuit Court
of the United States for that district, to assert the title of himself
and his family to freedom.

The declaration is in the form usually adopted in that State to try
questions of this description, and contains the averment necessary to
give the court jurisdiction; that he and the defendant are citizens of
different States; that is, that he is a citizen of Missouri, and the
defendant a citizen of New York.

The defendant pleaded in abatement to the jurisdiction of the court,
that the plaintiff was not a citizen of the State of Missouri, as
alleged in his declaration, being a negro of African descent, whose
ancestors were of pure African blood, and who were brought into this
country and sold as slaves.

To this plea the plaintiff demurred, and the defendant joined in
demurrer. The court overruled the plea, and gave judgment that the
defendant should answer over. And he thereupon put in sundry pleas in
bar, upon which issues were joined; and at the trial the verdict and
judgment were in his favor. Whereupon the plaintiff brought this writ
of error.

Before we speak of the pleas in bar, it will be proper to dispose of
the questions which have arisen on the plea in abatement.

That plea denies the right of the plaintiff to sue in a court of the
United States, for the reasons therein stated.

If the question raised by it is legally before us, and the court
should be of opinion that the facts stated in it disqualify the
plaintiff from becoming a citizen, in the sense in which that word is
used in the Constitution of the United States, then the judgment of
the Circuit Court is erroneous, and must be reversed.

It is suggested, however, that this plea is not before us; and that as
the judgment in the court below on this plea was in favor of the
plaintiff, he does not seek to reverse it, or bring it before the
court for revision by his writ of error; and also that the defendant
waived this defence by pleading over, and thereby admitted the
jurisdiction of the court.

But, in making this objection, we think the peculiar and limited
jurisdiction of courts of the United States has not been adverted to.
This peculiar and limite