An insurrection broke out in Canada in 1837, and a New York steamboat was chartered to bring supplies across the Niagara River to those engaged in it. One night when she was moored on the New York side of the river a party of loyal Canadians seized and burned her. During the accompanying affray an American was killed. A Canadian named McLeod, who was charged with having fired the fatal shot, was afterwards arrested in New York and indicted for murder. The British government then informed ours that it had ordered the burning of the steamer, and thereupon demanded McLeod's release. Our Secretary of State replied that the prosecution was in the hands of the State of New York, and the United States had no control over it. Lord Palmerston made the affair the subject of a dispatch, in which he stated that McLeod's execution would produce "a war of retaliation and vengeance." The President at once requested the Governor of New York to order a discontinuance of the prosecution. This was declined, but with a promise to grant a pardon in case of conviction.[Footnote: Lothrop, "Life of William H. Seward," 35.] The State courts refused to discharge the prisoner. He was tried on the original charge, but acquitted. Congress in 1842 did what it could to prevent the recurrence of such a conflict of authority by passing an Act giving the Circuit and District Courts of the United States jurisdiction on _habeas corpus_ proceedings in favor of foreigners held by State authority, who might claim a right of release under the principles of international law.[Footnote: U. S. Revised Statutes, Sec. 762.] The Circuit Court has since 1875 been given power to entertain original jurisdiction of any causes arising under the Constitution, laws or treaties of the United States, regardless of the citizenship of the parties, if a value of $2,000 is involved. In all cases, also, of imprisonment by State authority, whether under arrest before trial or after a sentence of conviction, in violation of rights claimed under the Constitution, laws or treaties of the United States, the prisoner may now be summarily discharged on a writ of _habeas corpus_ by a court or judge of the United States. Ordinarily, however, as a matter of comity, he will be left to seek his remedy in the State courts, and if without success there, on a writ of error from the Supreme Court of the United States.[Footnote: _In re_ Neagle, 135 U. S. Reports, 1; _Ex parte_ Royall, 117 U. S. Reports, 241.] The State courts have no power to release on _habeas corpus_ one who is held under the authority of the United States. If that authority has been illegally exerted, his remedy is in the federal courts alone.[Footnote: Ableman _v._ Booth, 21 Howard's Reports, 506.] The cases in which a State can be sued in an original suit in the Supreme Court of the United States are defined in the Constitution and, as limited by the eleventh amendment to it, are quite few.