The state courts are not excluded from the exercise of jurisdiction with reference to all of the classes of cases placed by the Constitution within the possible cognizance of the federal courts. Over a very large proportion of these cases Congress has not seen fit to confer jurisdiction on any federal court. As to certain of these cases the federal jurisdiction is held to be neces-sarilly exclusive, and it may by Congress be made so as to all, but as to others the state courts may be permitted to adjudicate concurrently. That is to say, as to these cases, the two systems of courts may at the same time have equal authority, the suitors being given the option as to which tribunals shall be resorted to.50

49 It would seem that Congress has the power to provide that this right of appeal from a state court may he had to an inferior federal court, but quite properly, in order to save as far as possible the States' sensibilities, an appeal only to the highest federal court has been allowed. And furthermore, as we have seen, this appeal lies only in those cases where the decision of the state court has been adverse to the federal right, privilege, or immunity.

This concurrence of jurisdiction is founded upon the fact as declared in Claflin v. Houseman51 that while every citizen of a State is a subject of two distinct sovereignties, these sovereignties are not foreign to each other but have concurrent authority as to place and persons though distinct as to subject-matters, and that therefore, as the court say: "Legal or equitable rights, acquired under either system of laws, may be enforced in any court of either sovereignty competent to hear and determine such kind of rights and not restrained by its Constitution in the exercise of such jurisdiction. Thus a legal or equitable right acquired under state laws, may be prosecuted in the state courts, and also, if the parties reside in different States, in the federal courts. So rights, whether legal or equitable, acquired under the laws of the United States, may be prosecuted in the United States courts, or in the state courts, competent to decide rights of the like character and class; subject, however, to this qualification, that where a right arises under the law of the United States, Congress may, if it see fit, give to the federal courts exclusive jurisdiction."

In the case of The Moses Taylor,52 decided in 1866, the Supreme Court with reference to the relation between the two systems of courts, declared as follows:

50 Subject, of course, to the right of removal from the state to the federal courts, and appeal to the Supreme Court of the United States by writ of error.

51 93 U. S. 130; 23 L. ed. 833.

52 4 Wall. 411; 18 L. ed. 397.

"How far this judicial power is exclusive, or may, by the legislation of Congress be made exclusive, in the courts of the United States, has been much discussed, though there has been no direct adjudication upon the point. In the opinion delivered in the case of Martin v. Hunter's Lessee (1 Wheat. 304; 4 L. ed. 97), Mr. Justice Story comments upon the fact that there are two classes of cases enumerated in the clause cited between which a distinction is drawn; that the first class includes cases arising under the Constitution, laws and treaties of the United States, cases affecting ambassadors, other public ministers and consuls, and cases of admiralty and maritime jurisdiction and that, with reference to this class, the expression is that the judicial power shall extend to all cases, but that in the subsequent part of the clause, which embraces all the other cases of national cognizance, and forms the second class, the word 'all' is dropped. And the learned justice appears to have thought the variation in the language the result of some determinate reason, and suggests that, with respect to the first class, it may have been the intention of the framers of the Constitution imperatively to extend the judicial power either in an original or appellate form to all cases, and, with respect to the latter class, to leave it to Congress to qualify the jurisdiction in such manner as public policy might dictate. Many cogent reasons and various considerations of public policy are stated in support of this suggestion. The vital importance of all the cases enumerated in the first class to the national sovereignty is mentioned as a reason which may have warranted the distinction, and which would seem to require that they should be vested exclusively in the National Courts - a consideration which does not apply, at least with equal force, to cases of the second class. Without, however, placing implicit reliance upon the distinction stated, the learned justice observes, in conclusion, that it is manifest that the judicial power of the United States is, in some cases, unavoidably exclusive of all state authority, and that in all others it may be made so at the election of Congress. We agree fully with this conclusion. The legislation of Congress has proceeded upon this supposition. The Judiciary Act of 1789, in its distribution of jurisdiction to the several federal courts, recognizes and is framed upon the theory that in all cases to which the judicial power of the United States extends, Congress may rightfully vest exclusive jurisdiction in the federal courts. It declares that in some cases, from their commencement, such jurisdiction shall be exclusive; in other cases it determines at what stage of procedure such jurisdiction shall attach, and how long and how far concurrent jurisdiction of the state courts shall be permitted. Thus, cases in which the United States are parties, civil causes of admiralty and maritime jurisdiction, and cases against consuls and vice-consuls, except for certain offenses, are placed, from their commencement, exclusively under the cognizance of the federal courts.

"On the other hand, some cases, in which an alien or a citizen of another state is made a party, may be brought either in a federal or a state court at the option of the plaintiff; and if brought in a state court may be prosecuted until the appearance of the defendant, and then, at his option, may be suffered to remain there, or may be transferred to the jurisdiction of the federal courts.

"Other cases, not included under these heads, but involving questions under the Constitution, laws, treaties, or authority of the United States, are only drawn within the control of the federal courts upon appeal or writ of error, after final judgment.

"By subsequent legislation of Congress, and particularly by the legislation of the last four years, many of the cases, which by the Judiciary Act could only come under the cognizance of the federal courts after final judgment in the state courts, may bo withdrawn from the concurrent jurisdiction of the latter courts at earlier stages, upon the application of the defendant.

"The constitutionality of these provisions cannot be seriously questioned, and is of frequent recognition by both state and federal courts."