 After embarking casualties and enemy prisoners, she departed 17 June and cruised northeast of Saipan while Vice Admiral Marc Mitscher's Fast Carrier Task Force defeated Admiral Ozawa's Mobile Fleet in the Battle of the Philippine Sea, the greatest carrier battle of the war.Following the resounding American victory, "James O'Hara" returned to Saipan 23 June; completed unloading cargo; and departed 24 June for Eniwetok and Pearl Harbor.Following additional amphibious training, "James O'Hara" departed in convoy 12 August and reached Guadalcanal the 24th.