The Continental Congress created the Continental Army on June 14, 1775, under the command of George Washington, making the Army the oldest branch of the U.S. armed forces. Today it is also the largest, with roughly 450,000 active-duty soldiers organized into divisions, brigades, and specialized commands responsible for the vast majority of sustained ground combat operations the United States conducts.

The Army's mission spans everything from armored warfare and infantry combat to logistics, medicine, cyber operations, and military intelligence, reflecting the sheer range of jobs needed to deploy and sustain a modern ground force anywhere in the world. Unlike the Navy and Air Force, which each run a single enlisted boot camp, the Army operates several Basic Combat Training posts to handle its much larger annual recruiting intake.

Counting the Army National Guard and Army Reserve, the total Army is close to a million people, and it offers roughly 190 enlisted job specialties (MOSs), the widest menu of any service. The Army also missed its recruiting goal by tens of thousands in 2022 and 2023 before rebounding, a shortfall that reshaped its incentives and led it to create the Future Soldier Prep Course for applicants who fall just short on fitness or academic standards.

The Army is a Department of the Army headed by a civilian Secretary of the Army, under the Secretary of Defense, with the four-star Chief of Staff of the Army as its senior uniformed officer. Its bases were among those renamed in 2023-25 (Fort Bragg to Fort Liberty and back, Fort Benning to Fort Moore, and others) as Congress and successive administrations changed the policy on installations named for Confederate officers.