The Army is one of the three military departments (Army, Navy, and Air Force) that reports to the Department of Defense. It's mission is to fight and win our Nation's wars and does this by “providing prompt, sustained land dominance across the full range of military operations and spectrum of conflicti n support of combat commanders”. This is accomplished, in part, by training, equipping, and organizing troops to fulfill their duties in combat operations as directed in Title 10 and Title 32 of the United States Code.

The Army is composed of the active military and the reserves, both equally important. The reserves consist of the United States Army Reserve and the Army National Guard. Both components of the Army conduct operational and institutional missions. The operational Army includes “the armies, corps, divisions, brigades, and battalions that conduct full spectrum operations around the world. The institutional Army supports the operational Army. Institutional organizations provide the infrastructure necessary to raise, train, equip, deploy, and ensure the readiness of all Army forces. The training base provides military skills and professional education to every Soldier—as well as members of sister services and allied forces. It also allows The Army to expand rapidly in time of war. The industrial base provides world-class equipment and logistics for The Army. Army installations provide the power-projection platforms required to deploy land forces promptly to support combatant commanders. Once those forces are deployed, the institutional Army provides the logistics needed to support them.”

The two missions of The Army, operational and institutional, would be of no purpose and would not be able to function one without the other.

The Army's Military Personnel Strength Levels in 1950 were counted at 593,167 and have dropped to the figure of 486,542 for 2002. The number of personnel peaked at over 1.5 million during the years 1951 - 1953 and 1968 - 1969, and over 1 million personnel during 1954 - 1956, 1962, 1966 - 1967, and 1970 - 1971. Except for those peak periods of warfare, the numbers have steadily declined from 997,994 in the year 1957 to the lowest ever of 480,801 most recently in 2001. Of the four Armed Services, The Army has consistantly maintained the highest number of personnel in its employ during any given year for which statistics were available.