The protection of federal law and federal rights against possible invasion by state law and state authorities may be secured in three ways. First, by vesting in the federal courts exclusive cognizance of all cases in which the enforcement of federal rights created or recognized by the Constitution, treaties, or congressional statutes, is involved; Second, by providing that all cases, involving these rights, which originate and are prosecuted in the state courts may be finally appealed to the federal courts; and, Third, by providing that such erases begun in the state courts may at some stage prior to final judgment therein, be removed into the federal courts. All these methods have been employed since the beginning of the present government.

47 Irvine v. Marshall, 20 How. 558; 15 L. ed. 994. 48 177 U. S. 505; 20 Sup. Ct. Rep. 726; 44 L. ed. 864.

In the early years under the Constitution chief reliance for the ultimate protection of federal rights against state invasion was laid upon the right of appeal to the Supreme Court of the United States by writ of error to the state courts having final jurisdiction of a case in which federal rights, privileges, and immunities were involved, and in which the final decision was adverse to the federal rights, privileges, and immunities claimed. With respect to very many matters of which jurisdiction might have been granted to the inferior federal courts, no such jurisdiction was given by Congress to the federal courts, these suits being left to the adjudication of the state courts, with the provision that certain cases might be removed into the federal courts, and that in all cases not so removed or removable, appeal might be had to the federal Supreme Court when the final state judgment was adverse to the alleged federal right, privilege, or immunity.49

Prior to 1887 by successive Acts of Congress the jurisdiction of the inferior federal courts had been amplified and the right of removal had been broadened, but in that year was passed an Act the purpose of which was to limit the right to bring a suit in the Circuit Court and the right to remove into that Court a suit brought in a state court. In construing this Statute the Supreme Court has uniformly kept in mind that its object is to limit the jurisdiction of the federal courts. As we have seen in previous chapters, the right of the federal courts to issue writs of habeas corpus directed to state authorities has been widened both by statute and judicial precedent.