54 FEDERAL anroaruu,
which this "dispute" is to be determined must arise under a law of
the United States. The value of "the matter in dispute," and not its
nature, is to be considered. But if the suit brought for the determi-
nation of this "dispute" necessarily involves the construction or ap-
plication of an act of congress, then such suit arises under such act.
As was said by this court in Hughes v. Northern Pacific Ry. O0. 9
Sawy. 319; S. C. 18 Fun. Bur. 106:
"A controversy which turns upon the existence, effect, or operation of an
act of congress, arises under such act, and a suit brought to determine the
same is a case arising under such act, within the meaning of the statute."
An action may be brought to recover the possession of a tract of
land. "The matter in dispute" in such action is the right to the land,
or the possession thereof. But that may depend on the legality or
effect of a prior sale of the premises for delinquent taxes under an
act of congress. In such case the action or controversy, without ref-
erence to the nature of the thing in dispute, arises under such act,
whether invoked bythe plaintiff or defendant, and is within the juris-
diction of the national courts. Nor is it material that other ques-
tions, in nowise depending upon the laws of the United States, are
involved in the determination of the case. As was said by Mr. Jus-
tice HARLAN in Railroad Co. v. Mississippi, 102 U. S. 141:
"lt is not sullicient to exclude the judicial power of the United States from
a. particular case. that it involves questions which do not at all depend on the
constitution or laws of the United States; but when a question to which the
judicial power of the Union is extended by the constitution forms an ingre-
dient of the original cause, it is within the power of congress to give the cir-
cuit courts jurisdiction of that cause, although other questions of fact or of
law may be involved in it."
Admitting, then, all that the plaintiffs claim in the argument,——~as
that the defendant cannot take advantage in this suit of any failure
on the part of the plaintiffs to reclaim these lands or pay the remain-
der ofthe purchase price, on the ground that they are conditions sub-
sequent to the grant or sale to the plaintiffs, for a breach of which no
one can complain but the state; and that the question of whether the
dam is a nuisance to these lands, or whether the plaintiffs are es-
topped to complain- thereof, or whether defendant has acquired a right
to flow these lands by prescription, are questions that do not arise
under any act of congress,-—still the plaintiffs case, on their own show-
ing, arises under the act of congress of March 12, 1800. They make
· . no claim to any right, title, or interest in these lands except under
this act, and in effect admit they have none other. Now, if the facts
do not bring them within the purview or operation of the act,-—as, if
the lands are not swamp or overflowed within the meaning of the same,
because the greater part thereof are not “ wet and unfit for cultivation,"
or theiright of the state thereto was lost by lapse of time long before
the passage of the act of October 26, 1870, because the selection
thereof was not made within two years from the adjournment of the