American history

Military History

The Military history of the United States spans a period of less than two and a half centuries. Over the course of those years, the United States grew from an alliance of thirteen British colonies without a professional military, to Earth's sole military superpower as of 2005.

Until the Constitutional Convention, the military presence in what became known as the United States was organized by each U.S. state as a voluntary or conscripted militia. As of 2005, the U.S. military consisted of an army, navy, air force and marine corps under the command of the United States Department of Defense. There also is the United States Coast Guard, which is controlled by the Department of Homeland Security. In each of these branches of military, the President of the United States is the commander in chief of the armed forces. In addition, each state has a national guard commanded by the state's governor and coordinated by the National Guard Bureau. The President of the United States has the authority during national emergencies to assume control of individual state national guard units.

The United States Constitution provided authority for the Congress to levy taxes and to raise a navy and national militia. Federal legislation eventually led to the modern nationalized system of military in the country. Historically, the amount of money the U.S. government spends on the military has often been a politically contentious issue.