[19] The Army's mission is "to fight and win our Nation's wars, by providing prompt, sustained land dominance, across the full range of military operations and the spectrum of conflict, in support of combatant commanders".

A number of European soldiers came on their own to help, such as Friedrich Wilhelm von Steuben, who taught Prussian Army tactics and organizational skills.

The Army fought numerous pitched battles, and sometimes used Fabian strategy and hit-and-run tactics in the South in 1780 and 1781; under Major General Nathanael Greene, it hit where the British were weakest to wear down their forces.

In 1798, during the Quasi-War with France, the U.S. Congress established a three-year "Provisional Army" of 10,000 men, consisting of twelve regiments of infantry and six troops of light dragoons.

The U.S. Army did not conquer Canada but it did destroy Native American resistance to expansion in the Old Northwest and stopped two major British invasions in 1814 and 1815.

[dubious – discuss] Two weeks after a treaty was signed (but not ratified), Andrew Jackson defeated the British in the Battle of New Orleans and siege of Fort St. Philip with an army dominated by militia and volunteers, and became a national hero.

[32] The U.S. victory resulted in acquisition of territory that eventually became all or parts of the states of California, Nevada, Utah, Colorado, Arizona, Wyoming and New Mexico.

[39][40] On the European front, U.S. Army troops formed a significant portion of the forces that landed in French North Africa and took Tunisia and then moved on to Sicily and later fought in Italy.

In the June 1944 landings in northern France and in the subsequent liberation of Europe and defeat of Nazi Germany, millions of U.S. Army troops played a central role.

Hundreds of thousands of U.S. troops remained stationed in West Germany, with others in Belgium, the Netherlands and the United Kingdom, until the 1990s in anticipation of a possible Soviet attack.

After repeated advances and retreats by both sides and the Chinese People's Volunteer Army's entry into the war, the Korean Armistice Agreement returned the peninsula to the status quo in July 1953.

U.S. forces effectively established and maintained control of the "traditional" battlefield, but they struggled to counter the guerrilla hit and run tactics of the communist Viet Cong and the People's Army of Vietnam (NVA).

Their objections included the inadequate maneuver element mix for those that remained and the end to the practice of rotating divisional commands among the states that supported them.

In 1990, Iraq invaded its smaller neighbor, Kuwait, and U.S. land forces quickly deployed to assure the protection of Saudi Arabia.

In January 1991 Operation Desert Storm commenced, a U.S.-led coalition which deployed over 500,000 troops, the bulk of them from U.S. Army formations, to drive out Iraqi forces.

[54] In response to the 11 September attacks and as part of the Global War on Terror, U.S. and NATO forces invaded Afghanistan in October 2001, displacing the Taliban government.

The U.S. Army also led the combined U.S. and allied invasion of Iraq in 2003; it served as the primary source for ground forces with its ability to sustain short and long-term deployment operations.

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.

[60] In response to Budget sequestration in 2013, Army plans were to shrink to 1940 levels,[61] although actual Active-Army end-strengths were projected to fall to some 450,000 troops by the end of FY2017.

[74] In the first one hundred years of its existence, the United States Army was maintained as a small peacetime force to man permanent forts and perform other non-wartime duties such as engineering and construction works.

[81] Since the adoption of the total force policy, in the aftermath of the Vietnam War, reserve component soldiers have taken a more active role in U.S. military operations.

In June 2013, the Army announced plans to downsize to 32 active brigade combat teams by 2015 to match a reduction in active-duty strength to 490,000 soldiers.

Beginning in 2021, all corporals will be required to conduct structured self-development for the NCO ranks, completing the basic leader course (BLC), or else be laterally assigned as specialists.

[184] Six events were determined to better predict which muscle groups of the body were adequately conditioned for combat actions:[185] three deadlifts,[189] a standing power throw of a ten-pound medicine ball,[190] hand-release pushups[191] (which replace the traditional pushup), a sprint/drag/carry 250 yard event,[192] three pull-ups with leg tucks (or a plank test in lieu of the leg tuck),[193][194] a mandatory rest period, and a two-mile run.

Individual-level replenishment still requires training at a unit level, which is conducted at the continental U.S. (CONUS) replacement center (CRC) at Fort Bliss, in New Mexico and Texas before their individual deployment.

This program is designed to assist potential recruits who may initially need to meet the Army's physical fitness or academic standards.

[208] The chief of staff of the Army has identified six modernization priorities, these being (in order): artillery, ground vehicles, aircraft, network, air/missile defense, and soldier lethality.

[236] The U.S. Army's principal artillery weapons are the M109A7 Paladin self-propelled howitzer[237] and the M270 multiple launch rocket system (MLRS),[238] both mounted on tracked platforms and assigned to heavy mechanized units.

[243] Under the Johnson-McConnell agreement of 1966, the Army agreed to limit its fixed-wing aviation role to administrative mission support (light unarmed aircraft which cannot operate from forward positions).

After years of complaints that it was not suited well for most work conditions, Army Chief of Staff General Martin Dempsey eliminated it for wear with the ACU in June 2011.