After American victories at Midway and Guadalcanal, the carrier fleets returned to Hawaii for a brief refit. Upon return, Admirals Nimitz and Spruance continued their drive north to Japan beginning with Gilbert and the Marshall Islands. The carrier fleets had one simple order, search and destroy the enemy. Using air superiority, the fighting Marines and a barrage from the many U.S. battleships, cruisers and destroyers, the mission was a success, but it came with a price as many American lives and supplies were lost.