The US Army is the branch of the U.S. Military primarily responsible for land-based operations.

On July 20, 2009, U.S. Secretary of Defense Robert Gates announced an increase of 22,000 U.S. Army troops over for the next three years. The move is to help with the strained resources due to the wars in Iraq and Afghanistan.http://www.reuters.com/article/latestCrisis/idUSN20130714

In early 2009, U.S. Army reports stated that a record number of American soldiers had committed suicide in 2008. The statistics showed that a confirmed 128 soldiers had taken their own lives and another 15 deaths were suspected suicides, but investigations into those deaths had not been completed. These numbers were the highest on record since the army began keeping suicide statistics in 1980.CNN: Army to report record number of suicides (January 28, 2009)

Centralized bases of operation (as of 2007):

1. United States Central Command (USCENTCOM)
2. United States European Command (USEUCOM)
3. United States Pacific Command (USPACOM)
4. United States Northern Command (USNORTHCOM)
5. United States Southern Command (USSOUTHCOM)

The Pentagon's inspector general recalled 16,000 sets of body armor on January 29, 2009. Army Secretary Pete Geren said the bullet-shielding plates in the armor failed to pass testing and could jeopardize the lives of soldiers. The recalled armor was produced between 2005 and 2007.FOXNews.com: U.S. Army to Recall 16,000 Sets of Armor...Safety Concerns (January 29, 2009)

In January 2008, the Army's Chief of Staff sent apology letters so the families of 7,000 soldiers who received letters addressed "Dear John Doe." The letters were accidentally mailed in late December 2008 by a private contractor. The letters, which included information for the families of the soldiers regarding offers of assistance, was intended to be addressed with the specific names of the soldiers who died in Operation Enduring Freedom (or Afghanistan War) and Operation Iraqi Freedom (or Iraq War).FOXNews.com: Army Apologizes for Letter Mishap to Families of Fallen...(January 7, 2008)

The Continental Army, which was raised in 1775 to fight the British during the Revolutionary War, was disbanded following the Treaty of Paris in 1782, when British forces withdrew from America. Because of deep-seated suspicion against standing armies, state militias were employed until 1791, when the present U.S. Army was organized (as the Legion of the United States) as a federal Indian-fighting force. A standard regimental structure was readopted in 1797, and continues to the present day.

The U.S. Army, which contains the U.S. National Guard and the Army Reserve, is (like all branches of the military) determined by the Constitution to fall under the command of the President of the United States. Under normal conditions, the Army National Guard is subdivided into over fifty state and territorial forces, each commanded by the governor of a U.S. state or territory. The civilian Secretary of Defense is next in the federal chain, followed by the civilian Secretary of the Army, underneath whom is the military Army Chief of Staff. Exceptions to this system are frequent and notable, one example of which is that operational forces may report directly to the Secretary of Defense.

In top-down order:

1. General of the Army (or five-star general) through a diminishing succession of generalships
2. Colonel
3. Lieutenant Colonel
4. Major
5. Captain
6. First Lieutenant
7. Second Lieutenant
8. Warrant Officer

Warrant officers are specialists more-or-less outside the chain of command, in roles (such as aircraft pilot) that demand expertise and situational authority. The enlisted ranks run through Sergeant Major of the Army through various administrative and/or specialist grades of sergeant, through Corporal, Specialist, Private First Class, and Private.