The Posse Comitatus Act is the United States federal law (18 U.S.C. § 1385, original at 20 Stat. 152) that was passed on June 18, 1878, after the end of Reconstruction and was updated in 1981. Its intent (in concert with the Insurrection Act of 1807) was to limit the powers of Federal government in using federal military personnel to enforce the State laws.
The Bill/Act as modified in 1981 refers to the Armed Forces of the United States. It does not apply to the National Guard under state authority from acting in a law enforcement capacity within its home state or in an adjacent state if invited by that state’s governor. The U.S. Coast Guard, which operates under the Department of Homeland Security, is also not covered by the Posse Comitatus Act, primarily because the Coast Guard has both a maritime law enforcement mission and a federal regulatory agency mission….More
**Prohibits the military from usurping police duties. Assumes the military shouldn’t be involved with civilians**