The Battle of Peleliu was one of the bloodiest battles fought by the United States against the Japanese during the Mariana and Palau Campaign in World War II. 

The battle, codenamed Operation Stalemate II, took place from September 15 to November 27, 1944. It involved the 1st Marine Division and the Army’s 81st Infantry Division. The National Museum of the Marine Corps called it “the bitterest battle of the war for the Marines.”

Even before the Battle of Peleliu, there was controversy over whether the operation was even necessary. The controversy continues to this day.

The battle was fought over the existence of an airstrip on the island and was part of Operation Forager, the larger Allied offensive campaign, which took place between June and November 1944 in the Pacific Theater.