▲The attack on Pearl Harbor in Hawaii on the morning of December 7, 1941 led to the United States' entry into World War II.

▲Pearl Harbor today features the USS Arizona Memorial, one of several sites in Hawaii that are part of the World War II Valor in the Pacific National Monument.

▲Makin Island as seen through the periscope of USS Nautilus. The attack by US Marine Corp raiders on Japanese forces in August 1942 was among the first American offensive ground combat operations of World War II.

▲Landing crafts pass supporting US warships as they approach Eniwetok Atoll during the six-day battle, which began on February 17, 1944.

▲After the end of World War II, Eniwetok was used for nuclear testing. The first hydrogen bomb was detonated here in 1952.

▲The code name given to the February 17–18, 1944 attack on Truk Lagoon. Pictured: Japanese shipping under air attack.

▲A key battle in the Pacific Campaign, fought from June 15 to July 9, 1944. Pictured are B-29 bombers at Isely Field, mid-1945.

▲The Second Battle of Guam marked the American recapture of this strategic island, fought in July and August 1944.

▲After intensive and bloody fighting that took place over the last week of July 1944, US forces had destroyed the islands' Japanese garrison.

▲The high number of casualties suffered by American forces during this brutal confrontation led many observers to describe Peleliu as the "bitterest" battle of the war for the Marines.

▲Taking place through much of September and October 1944, the battle is known for the US thrust on "The Bowl," a hill where the Japanese planned to make their last stand.

▲Today, the tiny limestone island is a popular surfing destination.

▲A major conflict, the initial invasion of Okinawa on April 1, 1945 was the largest amphibious assault in the Pacific Theater of World War II. Pictured: a US observation plane flies over the razed Naha, capital of Okinawa, May 1945.

▲Okinawa Island remained in American military possession until 1972.

▲The North Pacific Theater saw the Aleutian Islands Campaign commence on June 1942 when a small Japanese force occupied the islands of Attu and Kiska. Pictured: US military personnel hauling supplies on Attu, 1943.

▲This decisive naval battle took place just six months after the attack on Pearl Harbor, when the US Navy defeated an attacking fleet of the Imperial Japanese Navy between June 4-7, 1942.

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Immature Laysan albatrosses on Midway atoll. Lead poisoning is killing thousands of these birds annually due to chicks ingesting lead-based paint chips from buildings left behind by the US Navy.

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In 1972, Japanese Army Sergeant Shoichi Yokoi was discovered by hunters on the island. He had lived alone in a cave for 28 years.

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Tinian was the departure point for the B-29 bombers Enola Gay and Bocksar, which respectively dropped the two atomic bombs on Hiroshima and Nagasaki.

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Makin is now known as Butaritari Island, part of the island nation of Kiribati.

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Saipan today draws ornithologists from around the world to its incredible variety of endemic bird species. Pictured is the aptly-named Bird Island.

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This sheltered body of water is now known as Chuuk Lagoon and is part of the Federated States of Micronesia.

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The entire island is listed on the National Register of Historic Places as the Peleliu Battlefield.

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The MacArthur Landing Memorial National Park in Palo commemorates the historic landing.

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The campaign is known as the "Forgotten Battle" and was over within a year. Surviving elements of the islands' US military bases are National Historic Landmarks.

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Fought November 20-23, 1943, casualties numbered nearly 6,400 combatants from both sides. Pictured: Tarawa Atoll long range aircraft at Hawkins Field, on the small island of Betio.

▲The summit of Mount Suribachi is where victorious US Marines hoisted the American flag, a scene famously captured by photographer Joe Rosenthal.

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Victory over Japan Day, or VJ-Day, is commemorated as the day on which Japan surrendered in World War II.

The Pacific Ocean theater of World War II saw many bloody and brutal battles take place on land and sea between Allied forces and the Empire of Japan. Over 75 years later, reminders still exist of that terrible time in history.

Browse the gallery and see how war and peace shaped the Pacific Ocean region.

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The Battle of Tarawa marked the first major American offensive in the Central Pacific region and was the initial encounter in the Pacific War where US forces faced Japanese resistance during an amphibious landing.

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On October 20, 1944, the US Navy successfully landed four Sixth Army divisions onto the shores of Leyte. Although Japanese aerial counterattacks inflicted damage on the USS Sangamon and several other ships, they did not disrupt the landings.

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US forces advance towards Japanese cave positions in the north face of Mount Suribachi during the assault on Iwo Jima, which took place in February and March, 1945.