Federal jurisdiction (United States)

Federal jurisdiction refers to the legal scope of the government's powers in the United States of America.

The United States is a federal republic, governed by the U.S. Constitution, containing fifty states and a federal district which elect the President and Vice President, and having other territories and possessions in its national jurisdiction. This government is variously known as the Union, the United States, or the federal government.

Under the Constitution and various treaties, the legal jurisdiction of the United States includes territories and territorial waters.

One aspect of federal jurisdiction is the extent of legislative power. Under the Constitution, Congress has power to legislate only in the areas that are delegated to it. Under clause 17 Article I Section 8 of the Constitution however, Congress has power to "exercise exclusive Legislation in all cases whatsoever" over the federal district (Washington, D.C.) and other territory ceded to the federal government by the states, such as for military installations.

Federal jurisdiction in this sense is important in criminal law because federal law does not supersede state criminal law. Congress has enacted the Assimilative Crimes Act (18 U.S.C. § 13), which provides that any act that would have been a crime under the laws of the state in which a federal enclave is situated is also a federal crime. As most such enclaves are occupied by the military, military law is especially concerned with these enclaves, especially the issue of establishing who has jurisdiction and what type of jurisdiction. In such areas, the federal government may have proprietary jurisdiction (rights as landowner), concurrent jurisdiction (with federal and state law applicable), or exclusive jurisdiction over the land where an act was committed. Courts-martial involving military members subject to the Uniform Code of Military Justice apply regardless of location.

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