Civil Affairs Division

Civil affairs in the United States Armed Forces are civil-military operations (CMO) use of military force to control areas seized from the enemy (or a third party), minimize insurgency or civil interference with military operations, and maximize civil support for military operations. CMO is conducted in conjunction with combat operations during wartime and becomes a central part of a military campaign in counter-insurgencies. CMO operations have been in frequent use since 1775 by the Army, as well as more recently by the Navy and Marine Corps.

Civil-military operations (CMO) conducted by the U.S. Military were common in the colonial era in dealing with hostile Indians. They became major activities for the Continental Army in American Revolution. During that war, all sides employed civil affairs in every colony/state. Military authorities managed activities that civilians had managed prior to the war. The invasion of Canada in 1775 was an early example, The American invaders won considerable support from the locals, but failed to capture Quebec City and were forced to retreat in disarray.

In the U.S.-Mexican War, Lt. Gen. Winfield Scott could be considered the "Father of Civil Affairs." He displayed a deep respect for the Mexican people and their culture. Scott enjoyed great success in keeping civilian problems from interfering with military operations by issuing General Order No. 20 and ensuring the Provost Marshals office enforced it. The United States Army considers this to be where Civil Affairs (CA) originated.

The Army had large-scale CMO roles during the American Civil War, and for much of the Reconstruction Era until the last units were withdrawn in 1877.

At the end of the 19th century, and well into the 20th U.S. Army was involved in numerous military interventions in several of the Caribbean and Latin American nations before and after World War I. After the Spanish–American War ended in 1898, Maj. Gen. Leonard Wood restored order in Cuba with CA forces. The Army returned to Cuba in 1905, again in 1912, and starting in 1917, was there for a period of many years. It was again called upon to protect American interests by military intervention in the Dominican Republic (1916–1924), Haiti (1915–1934), and Nicaragua (1926–1934). The Army was also called to Panama in 1903 to ensure the birth of that nation when it broke away from Colombia to become independent.

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Wikipedia