Wildenhus’s Case was a United States Supreme Court case that dealt with the issue of whether a state court had the authority to issue a writ of habeas corpus to a prisoner held in federal custody. The case arose when a prisoner, Wildenhus, was held in federal custody in the District of Columbia. Wildenhus sought a writ of habeas corpus from the Supreme Court of the District of Columbia, which was denied. Wildenhus then appealed to the Supreme Court of the United States. The Supreme Court held that the state court did not have the authority to issue a writ of habeas corpus to a prisoner held in federal custody. The Court reasoned that the power to issue a writ of habeas corpus was a federal power, and that the state court did not have the authority to interfere with the federal government’s power. The Court also noted that the writ of habeas corpus was a fundamental right, and that the state court should not be allowed to interfere with the federal government’s power to protect this right. The Court’s decision in Wildenhus’s Case established that state courts do not have the authority to issue a writ of habeas corpus to a prisoner held in federal custody. This decision has been cited in numerous subsequent cases, and has been used to support the principle that the federal government has the power to protect the fundamental right of habeas corpus.

In Wildenhus's Case, the Supreme Court was asked to determine whether a citizen of New York who had been living in Washington D.C. for several years could be sued in a federal court located in Maryland. The majority opinion held that he could not because his residence did not meet the requirements of diversity jurisdiction under the Judiciary Act of 1789 and thus it lacked subject matter jurisdiction over him. Justice Field dissented from this decision, arguing that Congress intended to allow citizens residing outside their home state to be sued within any other district or circuit court as long as they were present at the time suit was brought against them and resided there with an intention to remain indefinitely. He argued that since Wildenhus met these criteria, he should have been allowed to be sued by virtue of having established residency within Maryland’s borders even if it wasn't permanent or indefinite enough for diversity jurisdiction purposes under existing law at the time