USS Idaho (BB-42), a New Mexico-class battleship shells Okinawa on 1 April 1945.
The largest amphibious assault in the Pacific Theater began April 1, 1945. Four divisions of the U.S. 10th Army (the 7th, 27th, 77th, and 96th) and two Marine Divisions (the 1st and 6th) fought on the island while the 2nd Marine Division remained as an amphibious reserve and was never brought ashore. British, Canadian, Australian and New Zealand air and naval personnel and resources also took part in this battle.
Army and Marine units landed April 1, 1945 and did not face heavy resistance (for Pacific Theater normal levels.)