The fourth USS Essex (CV 9) was launched on July 31, 1942 by Newport News Shipbuilding and Dry Dock Co. sponsored by Mrs. Artemus L. Gates, wife of the Assistant Secretary of the Navy for Air; and commissioned December 31, 1942, Captain D. B. Duncan commanding. She was reclassified as CVA 9 on October 1, 1952, and CVS 9 on March 8, 1960.

Following her shakedown cruise Essex sailed to the Pacific in May 1943 to begin a succession of victories which would bring her to Tokyo Bay. Departing Pearl Harbor, she participated with Task Force 16 (TF 16) in carrier operations against Marcus Island (August 31, 1943); was designated flagship of TF 14 and struck Wake Island (October 5-6); launched an attack with Task Group 50.3 (TG 50.3) against the Gilbert Islands where she also took part in her first amphibious assault, the landing on Tarawa (November 18-23). Refueling at sea, she cruised as flagship of TG 50.3 to attack Kwajalein (December 4). Her second amphibious assault delivered in company with TG 58.2 was against the Marshalls (January 29-February 2, 1944).

USS Essex in TG 68.2 now joined with TG 58.1 and 58.3, to constitute the most formidable carrier striking force to date, in launching an attack against Truk (February 17-18, 1944) during which eight Japanese ships were sunk. En route to the Marianas to sever Japanese supply lines, the carrier force was detected and received a prolonged aerial attack which it repelled in a businesslike manner and then continued with the scheduled attack upon Saipan, Tinian and Guam (February 23).

After this operation USS Essex (CV 9) proceeded to San Francisco for her single wartime overhaul. She then joined carriers USS Wasp (CV 18) and USS San Jacinto (CVL 30) in TG 12.1 to strike Marcus Island (May 19-20, 1944) and Wake (May 23). She deployed with TF 58 to support the occupation of the Marianas (June 12-August 10); sortied with TG 38.3 to lead an attack against the Palau Islands (September 6-8), and Mindanao (September 9-10) with enemy shipping as the main target, and remained in the area to supp ort landings on Peleliu. On October 2nd, she weathered a typhoon and 4 days later departed with TF 38 for the Ryukyus.

For the remainder of 1944 Essex continued her frontline action, participating in strikes against Okinawa (October 10), and Formosa (October 12-14), covering the Leyte landings, taking part in the battle for Leyte Gulf (October 24-25), and continuing the search for enemy fleet units until 30th when she returned to Ulithi, Caroline Islands, for replenishment. She resumed the offensive and delivered attacks on Manila and the northern Philippine Islands during November. On November 25th, for the first time in her far-ranging operations and destruction to the enemy, USS Essex (CV 9) received injury. A kamikaze hit the port edge of her flight deck landing among planes gassed for takeoff, causing extensive damage, killing 15, and wounding 44.

This "cramped her style" very little. Following quick repairs we find her with 3d Fleet off Luzon supporting the occupation of Mindoro (December 14-16). She rode out the typhoon on 18th and made special search for survivors afterwards. With TG 3 8.3 she participated in the Lingayen Gulf operations, launched strikes against Formosa, Sakishima, Okinawa, and Luzon. Entering the South China Sea in search of enemy surface forces, the task force pounded shipping and conducted strikes on Formosa, the China coast, Hainan, and Hong Kong. Essex withstood the onslaught of the third typhoon in four months (January 20-21, 1945) before striking again at Formosa, Miyako Shima and Okinawa (January 26-27).

During the remainder of the war she operated with TF 58, conducting attacks against the Tokyo area (16-17, and 25th) both to neutralize the enemy's airpower before the landings on Iwo Jima and to cripple the aircraft manufacturing industry. She sent support missions against Iwo Jima and neighboring islands, but from March 23 to May 28, 1945 was employed primarily to support the conquest of Okinawa.

In the closing days of the war, USS Essex took part in the final telling raids against the Japanese home islands (July 10- August 15, 1945). Following the surrender, she continued defensive combat air patrols until September 3rd when she was ordered to Bremerton, Wash., for inactivation. On January 9, 1947, she was placed out of commission in reserve.

Modernization endowed Essex with a new flight deck, and a streamlined island superstructure, on January 16, 1951 when recommissioned, Captain A. W. Wheelock commanding.

After a brief cruise in Hawaiian waters she began the first of three tours in Far Eastern waters during the Korean war. She served as flagship for Carrier Division 1 and TF 77. She was the first carrier to launch F2H Banshee twinjet fighters on combat missions; on September 16, 1951 one of these planes, damaged in combat, crashed into aircraft parked on the forward flight deck causing an explosion and fire which killed seven. After repairs at Yokosuka she returned to frontline action on October 3 to launch strikes up to the Yalu River and provide close air support for U.N. troops.

On December 1, 1953 she started her final tour of the war, sailing the China Sea with the Peace Patrol. From November 1954 to June 1955 she engaged in training exercises, operated for three months with the 7th Fleet, assisted in the Tachen Islands evacuation, and engaged in air operations and fleet manuevers off Okinawa.

In July 1955 USS Essex (CVA 9) entered Puget Sound Naval Shipyard for repairs and extensive alterations, including installation of an angled flight deck. Modernization completed, she rejoined the Pacific Fleet in March 1956. For the next 14 months the carrier operated off the west coast, except for a six-months cruise with the 7th Fleet in the Far East. Ordered to join the Atlantic Fleet for the first time in her long career, she sailed from San Diego on June 21, 1957, rounded Cape Horn, and arrived in Mayport, Fla., on August 1 .

In the fall of 1957 Essex participated as an anti-submarine carrier in the NATO exercises, Strike Back, and in February 1958 deployed with the 6th Fleet until May when she shifted to the eastern Mediterranean. Alerted to the Middle East crisis on July 14, 1958 she sped to support the U.S. Peace Force landing in Beirut, Lebanon, launching reconnaissance and patrol missions until August 20. Once again she was ordered to proceed to Asian waters, and transitted the Suez Canal to arrive in the Taiwan operational area where she joined TF 77 in conducting flight operations before rounding the Horn and proceeding back to Mayport.

May 28, 1959 A FJ Fury jet crashes aboard Essex, east off Jacksonville, Fla., causing explosions and fire, killing two, and injuring 21.

USS Essex joined with the 2nd Fleet and British ships in Atlantic exercises and with NATO forces in the eastern Mediterranean during the fall of 1959. In December she aided victims of a disastrous flood at Frejus, France.

In the spring of 1960 she was converted into an ASW Support Carrier and was thereafter homeported at Quonset Point, R.I. She operated as flagship of Carrier Division 18 and Antisubmarine Carrier Group Three. She conducted rescue and salvage operations off the New Jersey coast for a downed blimp; cruised with midshipmen, and was deployed on NATO and CENTO exercises. In November 1960, she joined the French navy in Operation Jet Stream.

November 11, 1966 USS Nautilus (SSN 571) collides with the USS Essex (CVS 9) while running submerged during underway replenishment exercises, 350 miles east of Morehead City, NC. Both ships return to port unassisted. The submarine receives extensive damage to its sail area and goes to New London, CT. The Essex sustains an open hull cut in the bow area and proceeds to Norfolk, VA.

USS Essex (CVS 9) was decommissioned Jun 30, 1969. She was stricken from the Navy List on Jun 1, 1973, and sold by the Defense Reutilization and Marketing Service (DRMS) for scrapping Jun 1, 1975.