Andrew Jackson (March 15, 1767 – June 8, 1845)
ever heard of the "PCA"
Effective: June 18, 1878
The
Posse Comitatus Act is a
United States federal law (
18 U.S.C. § 1385, original at 20
Stat. 152) signed on June 18, 1878, by
President Rutherford B. Hayes which limits the powers of the
federal government in the use of
federal military personnel to enforce
domestic policies within the
United States. The Act was passed as an amendment to an army
appropriation bill following the end of
Reconstruction and was updated in 1956 and 1981.
The Act specifically applies only to the
United States Army and, as amended in 1956, the
United States Air Force. Although the Act does not explicitly mention the
United States Navy and the
United States Marine Corps, the
Department of the Navy has prescribed regulations that are generally construed to give the Act force with respect to those services as well.
The Act does not prevent the Army National Guard or the Air 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
United States Coast Guard (under the
Department of Homeland Security) and
United States Space Force (under the
Department of the Air Force) are not covered by the Act either, primarily because although both are
armed services, they also have
maritime and
space law enforcement missions respectively.