The Battle of Tarawa (US code name Operation Galvanic) was a battle in the Pacific Theater of World War II, largely fought from November 20 to November 23, 1943. It was the first American offensive in the critical central Pacific region. It was also the first time in the war that the United States faced serious Japanese opposition to an amphibious landing. Previous landings met little or no initial resistance. 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 US had suffered similar casualties in other campaigns, for example over the six months in the campaign for Guadalcanal, but in this case the losses were suffered within the space of 76 hours. Nearly 6,000 Japanese and Americans died on the tiny island in the fighting.