The United States Navy (USN) is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S. Navy also has the world's largest carrier fleet, with 11 in service and one under construction. The service had 328,516 personnel on active duty and 101,689 in the Navy Reserve in January 2011. It operates 286 ships in active service and more than 3,700 aircraft.

The Navy traces its origins to the Continental Navy, which was established during the American Revolutionary War and was essentially disbanded as a separate entity shortly thereafter. The United States Constitution provided the legal basis for a military force by giving Congress the power "to provide and maintain a navy".

Depredations against American shipping by Barbary Coast pirates in the Mediterranean Sea spurred Congress to employ this power by passing the Naval Act of 1794 ordering the construction and manning of six frigates. These ships were used to end most pirate activity off the Barbary Coast. In the 20th century American blue-water navy capability was demonstrated by the 1907–1909 world tour of the Great White Fleet.

The 21st century United States Navy maintains a sizable global presence, deploying in such areas as East Asia, the Mediterranean, and the Middle East. It is a blue-water navy with the ability to project force onto the littoral regions of the world, engage in forward areas during peacetime, and rapidly respond to regional crises, making it an active player in American foreign and defense policy.

The US Navy is administratively managed by the Department of the Navy, which is headed by the civilian Secretary of the Navy. The Department of the Navy is itself a division of the Department of Defense, which is headed by the Secretary of Defense. Traditionally, the highest ranking Naval officer is the Chief of Naval Operations, a position currently held by Admiral Gary Roughead. However, today the highest ranking Naval Officer is the Chairman of the Joint Chiefs of Staff, Admiral Michael Mullen.

United States Navy
Active	October 13, 1775–Present
Country	United States
Branch	Navy
Size	433,500 personnel 289 ships 3,700+ aircraft 11 Aircraft carriers 10 Amphibious assault ships 9 Amphibious transport docks 12 Dock landing ships 22 Cruisers 55 Destroyers 30 Frigates 75 Submarines
Part of	Department of Defense Department of the Navy
Headquarters	The Pentagon
Motto	"Honor, Courage, Commitment" "Non sibi sed patriae" (Not self but country) (unofficial)
Colors	Blue, Gold
March	Anchors Aweigh
Engagements	Revolutionary War Quasi-War Barbary Wars War of 1812 Mexican-American War American Civil War Spanish-American War World War I World War II Korean War Vietnam War Persian Gulf War Kosovo War Afghanistan War Iraq War Somali War
Decorations	Presidential Unit Citation Navy Unit Commendation Meritorious Unit Commendation
Commanders
Chief of Naval Operations	ADM Gary Roughead
Vice Chief of Naval Operations	ADM Jonathan W. Greenert
Master Chief Petty Officer of the Navy	MCPON (SS/SW) Rick D. West
Aircraft flown
Attack	F/A-18A/B/C/D, F/A-18E/F
Electronic warfare	E-2C, EP-3E, E-6, EA-6B, EA-18G
Fighter	F/A-18A/B/C/D, F/A-18E/F
Helicopter	UH-1, SH-3, CH-53D, MH-53E, SH-60B/F, HH-60H, MH-60R/S
Patrol	P-3, P-8
Reconnaissance	RQ-2
Trainer	F-5, F-16N, T-2C, T-6, T-34, T-39, T-44, T-45, TH-57
Transport	C-2, C-12, C-20, C-40, C-130