The United States Navy (USN) is the maritime service branch of the United States Armed Forces and is designated as the navy of the United States in the Constitution. With 290 combat vessels, it is the world's second largest navy, behind the People's Liberation Army Navy, and by far the largest by displacement, at 4.5 million tons in 2021. It has the world's largest aircraft carrier fleet, with eleven in service, one undergoing trials, two new carriers under construction, and six other carriers planned as of 2024. The Navy is a part of the Department of Defense and is one of six armed forces and eight uniformed services of the United States.
The Navy originates from the Continental Navy, established in the American Revolutionary War. The Naval Act of 1794 provided for constructing six heavy frigates, the first ships of the Navy, in the prelude to the Barbary Wars. The American Civil War saw the blockade of the Confederacy and seizing control of its rivers. In World War II, the Navy was central in defeating the Imperial Japanese Navy in the Pacific War and Kriegsmarine U-boats in the Battle of the Atlantic, supplanting the Royal Navy as the world's largest navy. During the Cold War, the Navy, rivalled by the Soviet Navy, began providing nuclear deterrence via its ballistic missile submarines. The Navy was a major participant in the Korean and Vietnam Wars, and later the Gulf War, Yugoslav Wars and war on terror. A global power projecting blue-water navy, current large deployments include the Western Pacific, the Mediterranean, and the Indian Ocean, and it is able to rapidly respond to regional crises, making it a frequent actor in US foreign and military policy.
The Navy is part of the Department of the Navy, alongside the coequal United States Marine Corps, and is headed by the secretary of the Navy. The chief of naval operations (CNO) is the most senior Navy officer serving in the Department of the Navy. With 336,978 personnel on active duty and 101,583 in the Ready Reserve, the Navy is the third largest of US military service branches. The Navy maintains 290 deployable combat vessels as of 2023, including the world's largest fleet of nuclear-powered ships, between 11 aircraft carriers and 70 submarines. The world's largest naval aviation force with 4,012 operational aircraft, combat fleets include 471 F/A-18E/F Super Hornets and 458 Sikorsky MH-60 Seahawk helicopters. The Navy operates the Ohio-class submarines, which are assigned 1,895 nuclear warheads, representing 51% of the US nuclear stockpile and 19% of the global nuclear stockpile.
To recruit, train, equip, and organize to deliver combat ready Naval forces to win conflicts and wars while maintaining security and deterrence through sustained forward presence.
The Navy's three primary areas of responsibility are:
The preparation of naval forces necessary for the effective prosecution of war.
The maintenance of naval aviation, including land-based naval aviation, air transport essential for naval operations, and all air weapons and air techniques involved in the operations and activities of the Navy.
The development of aircraft, weapons, military tactics, technique, organization, and equipment of naval combat and service elements.
U.S. Navy training manuals state that the overall mission of the armed forces is "to be prepared to conduct prompt and sustained combat operations in support of the national interest." The Navy's five enduring functions are: sea control, power projection, deterrence, maritime security, and sealift.
It follows then as certain as that night succeeds the day, that without a decisive naval force we can do nothing definitive, and with it, everything honorable and glorious.
Would to Heaven we had a navy able to reform those enemies to mankind or crush them into non-existence.
Naval power . . . is the natural defense of the United States.
The Navy was rooted in the colonial seafaring tradition, which produced a large community of sailors, captains, and shipbuilders. In the early stages of the American Revolutionary War, Massachusetts had its own Massachusetts Naval Militia. The rationale for establishing a national navy was debated in the Second Continental Congress. Supporters argued that a navy would protect shipping, defend the coast, and make it easier to seek support from foreign countries. Detractors countered that challenging the British Royal Navy, then the world's preeminent naval power, was a foolish undertaking. Commander in Chief George Washington resolved the debate when he commissioned the ocean-going schooner USS Hannah to interdict British merchantmen and reported the captures to the Congress. On 13 October 1775, the Continental Congress authorized the purchase of two vessels to be armed for a cruise against British merchantmen; this resolution created the Continental Navy and is considered the first establishment of the U.S. Navy. The Continental Navy achieved mixed results; it was successful in a number of engagements and raided many British merchant vessels, but it lost twenty-four of its vessels and at one point was reduced to two in active service. In August 1785, after the Revolutionary War had drawn to a close, Congress had sold Alliance, the last ship remaining in the Continental Navy due to a lack of funds to maintain the ship or support a navy.
In 1972, the chief of naval operations, Admiral Elmo Zumwalt, authorized the Navy to celebrate its birthday on 13 October to honor the establishment of the Continental Navy in 1775.
From re-establishment to the Civil War
The United States was without a navy for nearly a decade, a situation that exposed U.S. merchant ships to attacks by the Barbary pirates. The sole armed maritime presence between 1790 and the launching of the U.S. Navy's first warships in 1797 was the U.S. Revenue-Marine, the primary predecessor of the U.S. Coast Guard. Although the United States Revenue Cutter Service conducted operations against the pirates, the pirates' depredations far outstripped its abilities and Congress passed the Naval Act of 1794 that established a permanent standing navy on 27 March 1794. The Naval Act ordered the construction and manning of six frigates and, by October 1797, the first three were brought into service: USS United States, USS Constellation, and USS Constitution. Due to his strong posture on having a strong standing Navy during this period, John Adams is "often called the father of the American Navy". In 1798–99 the Navy was involved in an undeclared Quasi-War with France. From 1801 to 1805, in the First Barbary War, the U.S. Navy defended U.S. ships from the Barbary pirates, blockaded the Barbary ports and executed attacks against the Barbary' fleets.
The U.S. Navy saw substantial action in the War of 1812, where it fought numerous engagements with Royal Navy. It emerged victorious in the Battle of Lake Erie and prevented the region from becoming a threat to American operations in the area. The result was a major victory for the U.S. Army at the Niagara Frontier of the war, and the defeat of Tecumseh's confederacy at the Battle of the Thames. Despite this, the U.S. Navy could not prevent the British from blockading its ports and landing troops. But after the War of 1812 ended in 1815, the U.S. Navy primarily focused its attention on protecting American shipping assets, sending squadrons to the Caribbean, the Mediterranean, where it participated in the Second Barbary War that ended piracy in the region, South America, Africa, and the Pacific. From 1819 to the outbreak of the Civil War, the Africa Squadron operated to suppress the slave trade, seizing 36 slave ships, although its contribution was smaller than that of the much larger Royal Navy. After 1840 several secretaries of the navy were southerners who advocated for strengthening southern naval defenses, expanding the fleet, and making naval technological improvements.
During the Mexican–American War the U.S. Navy blockaded Mexican ports, capturing or burning the Mexican fleet in the Gulf of California and capturing all major cities in Baja California peninsula. In 1846–1848 the Navy successfully used the Pacific Squadron under Commodore Robert F. Stockton and its marines and blue-jackets to facilitate the capture of California with large-scale land operations coordinated with the local militia organized in the California Battalion. The Navy conducted the U.S. military's first large-scale amphibious joint operation by successfully landing 12,000 army troops with their equipment in one day at Veracruz, Mexico. When larger guns were needed to bombard Veracruz, Navy volunteers landed large guns and manned them in the successful bombardment and capture of the city. This successful landing and capture of Veracruz opened the way for the capture of Mexico City and the end of the war. The U.S. Navy established itself as a player in United States foreign policy through the actions of Commodore Matthew C. Perry in Japan, which resulted in the Convention of Kanagawa in 1854.