A US Marine with a bullet hole in his helmet posing for a photo. Betio Island, Tarawa Atoll, Pacific theater, 1943.

The Battle of Tarawa was fought on 20–23 November 1943 between the United States and Japan at the Tarawa Atoll in the Gilbert Islands, and was part of Operation Galvanic, the U.S. invasion of the Gilberts. Nearly 6,400 Japanese, Koreans, and Americans died in the fighting, mostly on and around the small island of Betio, in the extreme southwest of Tarawa Atoll.

The Battle of Tarawa was the first American offensive in the critical Central Pacific region. It was also the first time in the Pacific War that the United States faced serious Japanese opposition to an amphibious landing. Previous landings had met little or no initial resistance  but on Tarawa the 4,500 Japanese defenders were well supplied and well prepared, and they fought almost to the last man, exacting a heavy toll on the United States Marine Corps. The losses on Tarawa were incurred within 76 hours.

For the next several days the 2nd Battalion, 6th Marines moved up through the remaining islands in the atoll and cleared the area of Japanese, completing this on 28 November. The 2nd Marine Division started shipping out soon after and were completely withdrawn by early 1944.

Of the 3,636 Japanese in the garrison, only one officer and sixteen enlisted men surrendered. 

Of the 1,200 Korean laborers brought to Tarawa to construct the defenses, only 129 survived. All told, 4,690 of the island's defenders were killed. The 2nd Marine Division suffered 894 killed in action, 48 officers and 846 enlisted men, while an additional 84 of the wounded survivors later succumbed to what proved to be fatal wounds. Of these, 8 were officers and 76 were enlisted men. A further 2,188 men were wounded in the battle, 102 officers and 2,086 men. Of the roughly 12,000 2nd Marine Division Marines on Tarawa, 3,166 officers and men became casualties.
Nearly all of these casualties were suffered in the 76 hours between the landing at 09:10 on 20 November and the island of Betio being declared secure at 13:30 23 November

The heavy casualties suffered by the United States at Tarawa sparked public protest, where headline reports of the high losses could not be understood for such a small and seemingly unimportant island. The public reaction was aggravated by the unguardedly frank comments of some of the Marine Corps command. General Hollander Smith, commander of the V Amphibious Corps  who had toured the beaches after the battle, likened the losses to Pickett's Charges at Gettysburg Admiral Chester Nimitz was inundated with angry letters from families of men killed on the island.