Ex parte Bollman, 8 U.S. (4 Cranch) 75 (1807), was a case brought before the United States Supreme Court. Bollman held that the constitutional definition of treason excluded mere conspiracy to levy war against the United States. The Supreme Court decided that "To constitute a levying of war, there must be an assemblage of persons for the purpose of effecting by force a treasonable purpose. Enlistments of men to serve against government is not sufficient."
Erick Bollman and Samuel Swartwout were civilians who became implicated in the Burr-Wilkinson Plot. This plot supposedly consisted of Aaron Burr and James Wilkinson attempting to create an empire in the United States, ruled by Burr. In 1806, Wilkinson informed President Thomas Jefferson of the plot, ending whatever may have actually been planned. Bollman and Swartwout attempted to recruit others into the plot, but these individuals informed the military, which promptly arrested them.
The Court first repudiated any jurisdiction for habeas not defined by statute or the Constitution of the United States: "[T]he power to award the writ by any courts of the United States, must be given by written law".
The Court found that the Judiciary Act, specifically section 14, was a substantive grant of the power to issue writs. The question the court answers is whether the statutory grant of power is limited to writs of habeas corpus that are "necessary to enable the courts of the United States to exercise their respective jurisdictions in some cause which they are capable of finally deciding".
Section 14 says justices of the supreme court and judges of the district courts "shall have power to grant writs of habeas corpus, for the purpose of an inquiry into the cause of commitment".
The Court cites William Blackstone to explain the function of different common law writs of habeas which are useless in the United States:
Concluding that the "general grant of power" is not limited to an exercise of jurisdiction in "causes which [the court] is enabled to decide finally", Marshall explains: "The only power then, which on this limited construction would be granted by the section under consideration, would be that of issuing writs of habeas corpus ad testificandum. The section itself proves that this was not the intention of the legislature."