The Constitution states: 'The judicial power of the United States shall be vested in one Supreme Court and in such inferior courts as the Congress may from time to time ordain and establish. The judicial power shall extend to all cases in law or equity arising under this Constitution, the laws of the United States,' &c. 'In all cases affecting ambassadors, other public ministers, and consuls, and those in which a State shall be a party, the Supreme Court shall have original jurisdiction. In all the other cases before mentioned, the Supreme Court shall have appellate jurisdiction, both as to law and fact, with exceptions, and under such regulations as the Congress shall make.' 'The privilege of the writ of habeas corpus shall not be suspended unless when in cases of rebellion or invasion the public safety may require it.' The first Congress by the 14th section of the act of September 24th, 1789 enacted: 'That all the before-mentioned courts shall have power to issue writs of scire facias, habeas corpus, and all other writs not especially provided for by statute, which may be necessary for the exercise of their respective jurisdictions, and agreeable to the principles and usages of law, and that either of the Justices of the Supreme Court, as well as Judges of the District Courts, shall have power to grant writs of habeas corpus for the purpose of and inquiry into the cause of commitment: Provided, That writs of habeas corpus shall in no case extend to prisoners in jail unless they are in custody under or by color of the authority of the United States, or are committed for trial before some court of the same, or are necessary to be brought into court to testify.' By the statute of 1833, the writ was extended to prisoners confined under any authority, whether State or National, for any act done or omitted in pursuance of a law of the United States, or of any order, process, or decree of any judge or court of the United States. By an act of 1842, it was extended to prisoners, being subjects or citizens of foreign states, in custody under National or State authority for acts done or omitted by or under color of foreign authority, and alleged to be valid under the law of nations. The act of 1867, provided: 'That the several courts of the United States, and the several justices and judges of such courts, within their respective jurisdictions, in addition to the authority already conferred by law, shall have power to grant writs of habeas corpus in all cases where any person may be restrained of his or her liberty, in violation of the Constitution, or of any treaty or law of the United States,' &c. The act proceeds: 'From the final decision of any judge, justice, or courts inferior to the Circuit Court, appeal may be taken to the Circuit Court of the United States for the district in which the said cause is heard, and from the judgment of said Circuit Court to the Supreme Court of the United States.' By an act of March 27th, 1868: 'That so much of the act, approved February 5th, 1867, entitled 'An act to amend an act to establish the judicial courts of the United States, approved September 24th, 1789,' as authorized an appeal from the judgment of the Circuit Court to the Supreme Court of the United States, or the exercise of any such jurisdiction by said Supreme Court on appeals which have been or may hereafter be taken, be, and the same is hereby, repealed.' A writ of habeas corpus upon the prayer of P, addressed to the Circuit Court was directed to certain military officers holding P in custody, commanding them to produce his body and abide by the order of the court. P was brought into court and the court was made aware that P had been arrested, and was held for trial, upon a charge of murder, by a military commission, under the act of Congress of the 2nd of March 1867, 'to provide for the more efficient government of the rebel States.' P was a private citizen of the State of Mississippi; and was being tried by the military commission, without a jury, and without presentment or indictment by a grand jury; and, that he was not, and never had been, connected to the military. The Court held that P’s detention was lawful and dismissed the writ. P appealed. The Attorney General sought a preliminary hearing on the issue of jurisdiction.