The Army is a core branch of a nation's armed forces, responsible for engaging enemy ground forces, and securing control of land, resources, and populations. Military organization within an army follows a hierarchical structure, scaling from small squads to larger formations like platoons, companies, battalions, brigades, divisions, corps, and armies. This structure ensures clear command and control, efficient resource allocation, and effective execution of operations. Formalized ranks within armies gained prominence with the Roman Army, which was organized into legions led by legates and centuries led by centurions.
The United States Army was established on June 14, 1775, even predating the Declaration of Independence. It comprises both an active force and a reserve force, including the Army National Guard and the United States Army Reserve. The U.S. Army's mission is to "deploy, fight and win our Nation's wars by providing ready, prompt and sustained land dominance". Today, there are 17 branches of the Army, each playing a crucial role in the Total Army concept. These branches include the Adjutant General, Air Defense Artillery, Armor, and many others, each with specialized functions such as personnel management, air defense, reconnaissance, and more.
