US Army Training

The United States Army (USA) is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services. The modern army has its roots in the Continental Army which was formed on 14 June 1775,[4] to meet the demands of the American Revolutionary War before the establishment of the United States. The Congress of the Confederation officially created the United States Army on 3 June 1784[5][6] after the end of the Revolutionary War to replace the disbanded Continental Army. The army considers itself to be descended from the Continental Army and thus dates its inception from the origins of that force.[4]
The primary mission of the army is "to fight and win our Nation's wars by providing prompt, sustained land dominance across the full range of military operations and spectrum of conflict in support of combatant commanders."[7] The army is a military service within the Department of the Army, one of the three military departments of the Department of Defense. The army is headed by the Secretary of the Army, and the top military officer in the department is the Chief of Staff of the Army. The highest ranking army officer is currently the Chairman of the Joint Chiefs of Staff. During fiscal year 2011, the Regular Army reported a strength of 546,057 soldiers; the Army National Guard (ARNG) reported 358,078 and the United States Army Reserve (USAR) reported 201,166 putting the combined component strength total at 1,105,301 soldiers.[3]
Origins
The Continental Army was created on 14 June 1775 by the Continental Congress as a unified army for the colonies to fight Great Britain, with George Washington appointed as its commander.[4] The army was initially led by men who had served in the British Army or colonial militias and who brought much of British military heritage with them. As the Revolutionary War progressed, French aid, resources, and military thinking influenced the new army. A number of European soldiers came on their own to help, such as Friedrich Wilhelm von Steuben, who taught the army Prussian tactics and organizational skills.
The army fought numerous pitched battles and in the South 1780--81 sometimes used the Fabian strategy and hit-and-run tactics, hitting where the enemy was weakest, to wear down the British forces. Washington led victories against the British at Trenton and Princeton, but lost a series of battles around New York City in 1776 and Philadelphia in 1777. With a decisive victory at Yorktown, and the help of the French, the Continental Army prevailed against the British.
After the war, though, the Continental Army was quickly given land certificates and disbanded in a reflection of the republican distrust of standing armies. State militias became the new nation's sole ground army, with the exception of a regiment to guard the Western Frontier and one battery of artillery guarding West Point's arsenal. However, because of continuing conflict with Native Americans, it was soon realized that it was necessary to field a trained standing army. The Regular Army was at first very small, and after General St. Clair's defeat at the Battle of the Wabash, the Regular Army was reorganized as the Legion of the United States, which was established in 1791 and renamed the "United States Army" in 1796.

21st century
After the September 11 attacks, and as part of the Global War on Terror, U.S. and NATO forces invaded Afghanistan in 2001, displacing the Taliban government.
The U.S. Army led the combined U.S. and allied Invasion of Afghanistan in 2001, and Iraq in 2003. In the following years the mission changed from conflict between regular militaries to counterinsurgency, resulting in the deaths of more than 4,000 U.S service members (as of March 2008) and injuries to thousands more.[23][24] 23,813 insurgents[25] were killed in Iraq between 2003--2011. The lack of stability in the theater of operations has led to longer deployments for Regular Army as well as Reserve and Guard troops.[citation needed]

The army's chief modernization plan was the FCS program. Many systems were canceled and the remaining were swept into the BCT modernization program.[citation needed] In response to Budget sequestration in 2013 the army is planned to shrink to a size not seen since the WWII buildup.[26]

Structure
The United States Army is made up of three components: the active component, the Regular Army; and two reserve components, the Army National Guard and the Army Reserve. Both reserve components are primarily composed of part-time soldiers who train once a month, known as battle assemblies or unit training assemblies (UTAs), and conduct two to three weeks of annual training each year. Both the Regular Army and the Army Reserve are organized under Title 10 of the United States Code, while the National Guard is organized under Title 32.