US Army

The US Army is a branch of the United States armed forces and it is mainly responsible for carrying out land-based military operations. The army came into existence on June 14, 1775, prior to the formation of the United States, to handle the crisis of the American Revolutionary War. In the Financial Year 2002, the US Army had 480,000 soldiers on active duty and 555,000 in reserve (350,000 in ARNG and 205,000 in USAR).

The US Army has two broad divisions - the Regulars and the Reserves. The United States National Guard is the regular armed force under the command of state governments. Since the Vietnam War, the use of both the Army Reserve and the National Guard has increased significantly.

A member of the US Army is officially called a ‘Soldier’, with the letter ‘S’ in capital. The Army has the following structure-
1. Field Army: usually four-star level.
2. Corps: consists of two or more divisions and organic support brigades. Commanders are at three-star level.
3. Division: commanders are generally two-star level.
4. Brigade or group: usually consists of three or more brigades commanded by Colonel.
5. Battalion or squadron: units are organized into battalions. Cavalry units are organized into squadrons. A Lieutenant Colonel commands a battalion-sized unit. A Command Sergeant Major provides supports.
6. Company or battery or troop: artillery units are arranged into batteries and cavalry units are formed into troops. A Captain leads a company-sized unit. A First Sergeant provides support.
7. Platoon: a lieutenant leads a platoon. A Sergeant First Class provides support.
8. Section: Staff Sergeants direct the sections.
9. Squad: Sergeants lead the squads.
10. Fire team: four Soldiers form a fire team. Usually Corporals lead the fire teams.

This structure in the US Army is based on the differences in functions. The active combat forces in army are Armor, Infantry, Cavalry and Special Forces. The support forces include Artillery, Aviation, Intelligence Corps, Corps of Engineers, Quartermaster Corps, Medical Corps, Transportation Corps, Judge Advocate General's Corps, Ordnance Corps, Adjutant General's Corps and Signal Corps.