On September 11, 2001, the USS Enterprise was cruising the Indian Ocean when news broke that the World Trade Center and Pentagon had been hit by hijacked airplanes.
The aircraft carrier was immediately turned around towards the Middle East, and for weeks carried out air raids on the terrorist cells believed to have carried out the attack.
When it comes to military might, America's greatest weapon is its large fleet of aircraft carriers that patrol the world and can respond to incidents in a matter of hours from international waters.
No other country in the world maintains a fleet as large as the U.S., giving America no uncertain advantage. There are currently 10 supercarriers in commission, two under construction and another in planning. The few countries that can afford to invest in aircraft carriers usually maintain just one - at the most two.
See how America's aircraft carriers have changed over the years, from one of the first launched in 1920 to the modern super carrier.
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The US Navy's first aircraft carrier, the USS Langley, with eight warplanes on deck, during a show of naval strength off Baltimore. The aircraft carrier was completed in 1920
Cruiser USS Santa Fe alongside Essex class aircraft carrier USS Franklin after it was hit by a Japanese divebomber, resulting in the death of 724 sailors in March 1945
Some of the 3,700 sailor crew and passengers covering the flight deck of the USS Saratoga as she sails out of the fog towards the Golden Gate Bridge, San Francisco on September 13 1945
The American aircraft carrier USS Midway pictured off Okinawa during qualification trials in 1951.
The USS Saipan pictured above in 1956. The Tawana-class carrier was decommissioned in 1977 and scrapped for metal
The USS Princeton aircraft carrier pictured off the coast of Seattle, Washington above. The Princeton was sunk in World War II
The USS Independence aircraft carrier pictured above. The Independence was used during World War II and later used as a target in nuclear testing
The USS Hornet aircraft carrier. The Essex-class carrier has since been turned into a museum in Alameda, California
A flight deck crewman (left) aboard the aircraft carrier USS Ranger signals as a skyraider is placed on a catapult; other crewmen make final checks, March 24, 1965
An image of the Aircraft Carrier USS Wasp burning after being struck by three torpedoes from the Japanese submarine I-19 in the Coral Sea, September 15, 1942
View of flight crews around a pair of Grumman F4F-4 Wildcat fighter planes onboard an unidentified aircraft carrier (possibly the USS Ranger) in the early 1940s
Aircrew from the USS John F Kennedy are lifted from the flight deck during Special Purpose Insertion/Extraction (SPIE) exercise on February 26, 2002
An HH-60H Seahawk assigned to the 'Nightdippers' of Helicopter Anti-Submarine Squadron Five (HS-5) crosses the bow of the USS John F Kennedy as it enters the Mediterranean Sea on February 23, 2002
The Nimitz-class aircraft carrier USS Abraham Lincoln (CVN 72) cruises off the coast of San Diego while conducting routine carrier operations on November 10, 2005
Lightning storms rage over the flight deck of the Nimitz-class aircraft carrier USS John C. Stennis (CVN 74) as the ship transits the Arabain Gulf on March 28, 2007
In this handout image provided by the U.S. Navy, the aircraft carrier USS Kitty Hawk (CV 63) departs Yokosuka, Japan for the final time on May, 28, 2008
The former aircraft carrier USS Saratoga prepares for her final voyage from Newport Naval Station to a dismantling facility in Brownsville, Texas on August 21, 2014
he aircraft carrier USS Ronald Reagan (CVN 76) departs Joint Base Pearl Harbor-Hickam on August 3, 2014 after participating in Rim of the Pacific (RIMPAC) Exercise. RIMPAC is the world's largest international maritime exercise and takes place in and around the Hawaiian Islands
A shooter launches an F/A-18E Hornet assigned to the Thunderbolts of Marine Fighter Attack Squadron (VMFA) 251 from catapult two aboard the aircraft carrier USS Enterprise on September 26, 2012.
The aircraft carrier USS Theodore Roosevelt departs Naval Station Norfolk for a scheduled deployment on Tuesday March 11, 2015
Sailors and Marines man the rails aboard the Nimitz-class aircraft carrier USS Theodore Roosevelt (CVN 71) on March 11, 2015 as the ship departs her homeport in Norfolk for an around-the-world deployment to their new homeport in San Diego. The Theodore Roosevelt Carrier Strike Group will conduct operations in the U.S. 5th, 6th and 7th Fleet areas of responsibility
The aircraft carrier USS Theodore Roosevelt (CVN 71) departs Naval Station Norfolk for a scheduled deployment on March 11, 2015
The decommissioned Forrestal-class aircraft carrier ex-Ranger (CV 61) is towed away from Naval Base Kitsap-Bremerton on March 5, 2015. Ranger is being towed to Brownsville, Texas, for dismantling
A rainbow forms over the bow of the Nimitz-class aircraft carrier USS John C. Stennis (CVN 74) on February 3, 2015
Now India joins the aircraft carrier club: New ship launched just days after Japan showed off its new 'flat top' destroyer
India has launched its first home-built aircraft carrier today as it continues to bolster its maritime presence.
It joins the U.S., Russia, France and Britain in building its own carrier, which was launched at the Kochi shipyard in southern Kerala state.
However, INS Vikrant stills needs to be outfitted and extensive trials will be held in 2016 before the carrier is inducted into the Indian navy in 2018.
Britain said last November that its £280million-a-year aid programme to India would be halted in 2015, in light of the country's booming economy.
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Naval milestone: Indian launched its first domestically built aircraft carrier at a shipyard in Kochi, Kerala state, on Monday
Proud day: The Indian Navy said the INS Vikrant, which dwarfs other ships, is its 'crowning glory' and the launch marks the end of the first phase of construction
Enormous: MiG-29K, Light Combat Aircraft and Kamov 31 could fly from the 37,000 tonne carrier
On Saturday, India activated an atomic reactor for its domestically built nuclear submarine.
The carrier launch comes just six days after Japan launched a new ship capable of carrying 14 helicopters at once - although Japanese officials insisted the giant vessel is an aircraft carrier and said it will not be used to launch military jets.
The launch marked the end of the first phase of construction.
The 37,000 tonne INS Vikrant will now be moved to another dock for further construction.
MiG-29K, Light Combat Aircraft and Kamov 31 will be able to fly from the vessel when it is complete.
Vice-Admiral R.K. Dhowan, the vice-chief of Naval Staff said the vessel is the 'crowning glory' of the Indian Navy's construction programme.
Maritime giant: INS Vikrant docked at the Cochin Shipyard will be more than 850ft long and have a breadth of 196ft when it is complete
Elite list: India now joins a group of just four other countries - the U.S., Russia, France and Britain - capable of building an air craft carrier
Next step: Tugboats guide the carrier as it leaves the dock of the Cochin. It will be re-docked where it will be outfitted and undergo trials
Spurred on: India's rivalry with neighbouring China has seen it build up its naval capabilities in recent years
It is more than five times larger than any other ship built in India.
Once complete the ship will be more than 850ft (260m) long, with a breadth of 196ft (60m).
The ship's production work began in November 2006. It has been designed by the Directorate of Naval Design.
Vice Admiral K. Nair, Controller Warship Production and Acquisition, said: 'We have built 6,000 to 7,000 tonnage capacity ships so far. This is 37,500 tonnes.'
He said they had encountered a number of issues during the first phase of construction.
Vice Admiral Nair said: 'Availability of steel, problems with acquisition of machines were some of them.
'Most of the equipment has gone on board while the weapons have to be inducted. It has got ski jump from where aircraft will take off.'
Commodore K. Subramaniam, Cochin Shipyard chairman and managing director, said the next phase will include laying of electric cables, ventilation systems and setting up about 2,300 compartments and will take about four years to complete.
Diesel generators and gas turbines, capable of lighting up the whole of Kochi, have already been installed.
The Indian naval milestone comes amid rising tensions in the region between China and Japan.
Warship: Japan's new destroyer 'Izumo', which has a flight deck 820ft long (250m), was unveiled in Yokohama, south of Tokyo, last week
Izumo: Japan's naval authorities insist the flat-top destroyer is not an aircraft carrier despite bearing a strong resemblance to the vessel
The Japanese launched its destroyer last week after calls in the country for beefed-up naval and air forces to enable it to enforce its territorial claims against China.
The 250m vessel, named 'Izumo', is officially labelled a destroyer, although it has a flat top which functions as a flight deck like that on an aircraft carrier.
The unveiling of the new destroyer - which has been under development since 2009 - also coincides with a dispute between Japan and China over a chain of tiny islands in the South China Sea.
The two countries conduct regular patrols of the waters around the islands, which are called the Senkakus in Japan and the Diaoyus in China.
In November, China took a step towards achieving its ambition of becoming a leading naval power after successfully landing a fighter jet on an aircraft carrier for the first time.
The carrier is China's first and was bought from the Ukraine but the country is planning to build its own.
China spent ten years refurbishing the carrier, named Liaoning, after buying the unfinished former Soviet navy ship in 1998.
Britain's Royal Navy has four ships which form the core of its amphibious fleet - helicopter carriers HMS Illustrious and Ocean, and assault ships HMS Albion and Bulwark.