The United States Coast Guard (under the Department of Homeland Security) is not covered by the Act either, primarily because although it is an armed service, it also has a maritime law enforcement mission.
The title of the Act comes from the legal concept of posse comitatus, the authority under which a county sheriff, or another law officer, can conscript any able-bodied person to assist in keeping the peace.
[1] However, in the former Confederate States, many paramilitary groups sought to suppress, often through intimidation and violence, African-American political power and return the South to rule by the predominantly white Democratic Party.
[3] After President Hayes used federal troops to end the Great Railroad Strike of 1877, there was sufficient bipartisan support to pass what became the Posse Comitatus Act.
The Arkansas governor had opposed desegregation after the United States Supreme Court ruled in 1954 in Brown v. Board of Education that segregated public schools were unconstitutional.
The Enforcement Acts, among other powers, allowed the president to call up military forces when state authorities were either unable or unwilling to suppress violence that was in opposition to the citizens' constitutional rights.
§ 502(f)(2)(a),[11] which says National Guard troops may engage in "support of operations or missions undertaken by the member's unit at the request of the President or Secretary of Defense."
[12] In 2020, U.S. Representative Adam Schiff introduced an amendment to the Act to expand its coverage to include the U.S. Navy, Marine Corps, and Space Force.
From and after the passage of this act it shall not be lawful to employ any part of the Army of the United States, as a posse comitatus, or otherwise, for the purpose of executing the laws, except in such cases and under such circumstances as such employment of said force may be expressly authorized by the Constitution or by act of Congress; and no money appropriated by this act shall be used to pay any of the expenses incurred in the employment of any troops in violation of this section and any person willfully violating the provisions of this section shall be deemed guilty of a misdemeanor and on conviction thereof shall be punished by fine not exceeding ten thousand dollars or imprisonment not exceeding two years or by both such fine and imprisonment.
These include: Although it is an armed service,[21] the U.S. Coast Guard, which operates under the United States Department of Homeland Security during peacetime, is not restricted by the Posse Comitatus Act and has explicit authority to enforce federal law.
[8] Federal troops have a long history of domestic roles, including occupying secessionist Southern states during Reconstruction and putting down major urban riots.
[1] On March 10, 2009, members of the U.S. Army Military Police Corps from Fort Rucker were deployed to Samson, Alabama, in response to a shooting spree.