Japan withdrew from the League of Nations in 1935 after it had virtually annexed the Islands into the Empire. By 1936 a thriving fishing industry had developed as well as a sugar industry which occupied 68 percent of the arable land on Saipan, 80 percent on Tinian and 33 percent on Rota. The resident population grew to 23,800 on Saipan (of which only 3,222 were originally from the islands); 1,530 on Tinian (25  Chamorros) and 5,600 on Rota (791 Chamorros). By the time the dark clouds of war had gathered over the western Pacific, some 29,692 Japanese military personnel were garrisoned on Saipan. The islands were assaulted by American forces on June 15, 1944 and one of the most hotly contested battles of the entire war was fought on its sandy beaches and mountainous terrain.  American forces gained control of the island on July 1944  and the construction of bases and airfields began. It was from such airfield on Tinian that the first nuclear weapon was dropped on Hiroshima by the B -29 aircraft Enola Gay hastening the end of hostilities.  The airfields on Tinian which in 1945 were the busiest in the world are now largely abandoned. The CNMI Guide would like to thank Mr. William H. Stewart for providing all the information used in these pages.