Posse Comitatus Act (1878)

views updated May 11 2018

Posse Comitatus Act (1878)

Michael I. Spakand Donald F. Spak

Posse comitatus means "the power or force of the county." The term refers to a doctrine of ancient English common law authorizing a sheriff to summon the assistance of the able-bodied male population above the age of 15. Appointed special deputies, these men would aid the sheriff in keeping the peace, executing writs, quelling riots, capturing felons, and otherwise enforcing the laws. Unlike the organized militia, a posse was usually gathered as needed. The practice continued in the United States, as the posse became a necessary American colonial and frontier tradition.


Before 1878, it was common for the United States Army to enforce civilian laws. In frontier territories, the army was often the only source of law enforcement, supplemented by occasional U.S. Marshals. Over time, marshals and county sheriffs regularly called upon the army to assist in enforcing the laws. In 1854, for example, the U.S. attorney general wrote that the posse comitatus includes every male person above the age of 15, including the military:

Whatever may be their occupation, whether civilian or not, and including the military of all denominations, militia, soldiers, marines, all of whom are alike bound to obey the commands of a sheriff or marshal. The fact that they are organized as military bodies, under the immediate command of their own officers, does not in any wise affect their legal character. They are still the posse comitatus.

Soldiers were called upon to assist in catching fugitive slaves, as well as to guard polling places in federal elections. During the Reconstruction period that followed the Civil War, the army, initially under the command of General Ulysses S. Grant (who was later elected president), occupied the South.

By the time of the 1876 presidential election, Southern states were reconstituted. Many Southerners opposed both Grant, the outgoing Republican president, and Rutherford B. Hayes, the Republican presidential candidate. Federal troops actively assisted U.S. Marshals in patrolling and monitoring polling places in the South, claiming to be enforcing the federal election laws and preventing former Confederate officers from voting (as was the law at that time). Following bitter election contests in four Southern states, Hayes won the presidency by one electoral vote. Many felt that the federal troops, which supported Hayes and the Reconstructionist Republican candidates for Congress, intimidated Southerners who would have voted for Samuel Tilden, the Democratic candidate.

The resulting Democratic Congress was at odds with the Republican President Hayes. In response to what was seen as undue influence over the 1876 election, Congress outlawed the practice of posse comitatus by enacting the Posse Comitatus Act (PCA) (as 20 Stat. 152) as a rider to the Army Appropriation Act for 1880. The act stated: "Whoever, except in cases and under circumstances expressly authorized by the Constitution or Act of Congress, willfully uses any part of the Army or the Air Force as a posse comitatus or otherwise to execute the laws shall be fined under this title or imprisoned not more than two years, or both."

Congressional debates indicate that the PCA was intended to stop army troops from answering the call of a marshal to perform direct law enforcement duties and aid in execution of the law. Further legislative history indicates that the more immediate objective was to put an end to the use of federal troops to police elections in ex-Confederate states where civil power had been reestablished.

Significantly, President Hayes vetoed the act because it "makes a vital change in the election laws of the country, which is in no way connected to the use of the Army." Congress overrode the veto. Accordingly, the willful use of the army or air force as a posse comitatus or otherwise to execute the laws is a felony, unless the use is expressly authorized by the Constitution or an act of Congress.


The PCA directly applies only to the army and air force, without mentioning the navy, the Marine Corps, the Coast Guard, or the National Guard. The National Guard is subject to Article I, section 8 of the Constitution, "To provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions." The National Guard is under state control until called into federal service, and is authorized to enforce the laws upon the request of a governor.

Because the Coast Guard has a law enforcement function and is not under the control of the Department of Defense, it is not subject to the PCA. Although the naval service is not mentioned in the PCA, Department of Defense regulations extend the PCA to the navy and Marine Corps.

Although the president has constitutional power to use the military to protect the nation in time of emergency and to repel invasions, in the Civil Disturbance Statutes Congress expressly authorized the president to use the armed forces under emergency circumstances. Where there is an insurrection in a state against its government, the president may, in addition to calling out the militia, "use such of the armed forces as he considers necessary to suppress the insurrection." Also, the president may use the armed forces to suppress a rebellion, insurrection, domestic violence, or unlawful conspiracy that obstructs the execution of the laws of the United States or deprives the people of the United States from their constitutional rights, privileges, and immunities. These statutes were relied on to authorize the use of federal troops to enforce federal court orders for school desegregation in Arkansas (1957), Mississippi (1962), and Alabama (1963), as well as to assist the National Guard in quelling urban riots.

Other statutory exceptions allow active use of the armed forces to remove persons wrongfully settling on Native American lands, and in emergency situations to actively enforce federal laws prohibiting the illegal possession and use of radioactive material. Other laws allow the president to direct the armed forces actively to enforce specific federal laws.

The PCA was originally intended to eliminate the direct active use of federal troops by law enforcement officers. The act does not prohibit the use of military supplies or equipment. To this end, Congress passed various laws expressly authorizing the use of military equipment and supplies by civilian law enforcement, with the accompanying use of military personnel to maintain and operate the equipment being used in civilian law enforcement. For example, military drug-sniffing dogs were designated as equipment, and military dog handlers operating the equipment have been lent to the Drug Enforcement Agency and other law enforcement agencies. Military equipment may be used for aerial reconnaissance, interception of aircraft and vessels, and in operations against terrorists, drug traffickers, prohibited narcotics and drugs, weapons of mass destruction, and components of weapons of mass destruction. Additionally, the military may share with civilian law enforcement "any information collected during the normal course of military training or operations that may be relevant to a violation of any federal or state law within the jurisdiction of such officials."


Debate is ongoing as to whether the PCA should be repealed, moderated, or strengthened. Some argue that the act should be repealed because the federal government needs the full force of a flexible military to combat terrorism within the territorial United States. Others suggest the act is obsolete and should be repealed because numerous legislative exemptions have eroded the underlying policy and left the PCA a hollow shell. Others insist that although there are many exceptions, the act is essential to bar misuse of the military by civilian authorities and to prevent a military dictatorship from assuming control of the nation through use of the armed forces. Still others argue that the act means only that federal military forces may not be commandeered by civilian authorities for use in active and direct law enforcement as a posse comitatus. If local authorities need military personnel for specialized operations enforcing state laws, it is argued, they may call on the state governor for the assistance of the state National Guard.

See also: National Guard Acts.


Baker, Bonnie."The Origins of the Posse Comitatus." Air and Space Power Chronicles (1999). Online at <http://www.airpower.maxwell.af.mil/airchronicles>.

Hammond, Matthew Carlton. "The Posse Comitatus Act: A Principle in Need of Renewal." 75 Washington University Law Quarterly 953 (1997). Online at <http://law.wustl.edu/WULQ/75-2/752-10.html>.

Library Notes on Posse Comitatus (2002). Naval War College. <http://www.nwc.navy.mil/library>.

Quillen, Chris. "Posse Comitatus and Nuclear Terrorism, Spring 2002 Parameters." U.S. Army War College Quarterly 60 (2002). U.S Army. <http://carlisle-www.army.mil/usawc/Parameters/02spring/quillen.htm>.

Trebilcock, Major Craig T. "The Myth of Posse Comitatus." Journal of Homeland Security (2000). <http://homelandsecurity.org/journal>.

The Posse Comitatus Act

views updated Jun 08 2018

The Posse Comitatus Act (1878)prohibited use of the U.S. Army to aid civil officials in enforcing the law or suppressing civil disorder unless expressly ordered to do so by the president. Southern Democratic members of the House who resented widespread use of federal troops during Reconstruction introduced the law. Some northern congressmen supported the law due to the army's role in suppressing disorders during the 1877 railroad strike.

In the past, soldiers had occasionally served as posses to assist U.S. marshals or judges without reference to the president. During the 1850s, U.S. Attorney General Caleb Cushing ruled that U.S. marshals could call upon federal soldiers, Marines, and sailors to help enforce the Fugitive Slave Act in the North. Such troops performed similar duties when called on by territorial governors in Kansas and Utah. Regulars routinely acted as posses during Reconstruction in the South, particularly during election disorders. Troops suppressing the 1877 railroad riots took orders from state governors and even municipal officers.

Use of federal troops as a posse comitatus placed them outside the military chain of command and the commander in chief's direct authority. Too often the practice turned regulars into policemen serving the interests of locals directly involved in the disputes provoking disorder. Army officers welcomed the Posse Comitatus Act and the new regulations it engendered, for they felt more comfortable performing their duty safely within the chain of command. The provisions of the act have governed army regulations and civil disorder doctrine to the present.
[See also Civil‐Military Relations; Commander in Chief, President as.]


Robert W. Coakley , The Role of Federal Military Forces in Domestic Disorder, 1789–1878, 1988.
Jerry M. Cooper , Federal Military Intervention in Domestic Disorders, in Richard H. Kohn, ed., The United States Military Under the Constitution of the United States, 1789–1989, 1991.

Jerry Cooper