Operation Downfall was the proposed Allied plan for the invasion of the Japanese home islands near the end of World War II. The operation had two parts, Operation Olympic, intended to capture the southern third of the southernmost main Japanese island, Kyūshū, and Operation Coronet, the planned invasion of the Kantō Plain, near Tokyo, on the main Japanese island of Honshu. Olympic was scheduled for November 1945, to be followed by Coronet in early 1946. If Downfall had taken place, it would have been the largest amphibious operation in history, surpassing D-Day. The planned operation was canceled when Japan surrendered following the atomic bombings of Hiroshima and Nagasaki, the Soviet declaration of war, and the invasion of Manchuria. Order of Battle for Olympic Allied Supreme Commander, Allied Forces Pacific General Douglas MacArthur Ground forces Should these four corps prove insufficient to accomplish the tasks assigned, elements earmarked for Coronet would be used to reinforce Sixth Army at the rate of three divisions per month beginning about 30 days after the initial landings. Sixth Army General Walter Krueger Peripheral landings 40th Infantry "Sunburst" Division (Landing on Yakushima and Koshikijima Islands) 158th Infantry Regiment (Landing on Tanegashima) I Corps (Landing at Miyazaki) Major General Innis P. Swift 25th Infantry "Tropic Lightning" Division 33rd Infantry "Illinois" Division 41st Infantry "Sunsetters" Division V Amphibious Corps (Landing at Kushikino) Major General Harry Schmidt, USMC 3rd Marine Division (Bougainville, Guam, Iwo Jima) 4th Marine Division (Kwajalein, Saipan/Tinian, Iwo Jima) 5th Marine Division (Iwo Jima) XI Corps (Landing at Ariake) Major General Charles P. Hall 1st Cavalry Division Americal Division 43rd Infantry "Winged Victory" Division IX Corps (Reserve afloat) Major General Charles W. Ryder 81st Infantry "Wildcat" Division 98th Infantry "Iroquois" Division Follow-up units: 11th Airborne Division 77th Infantry Division Naval forces Third Fleet Admiral William F. Halsey 20 fleet and light aircraft carriers 9 battleships 26 cruisers 75 destroyers incl. British Pacific Fleet 6 fleet and light carriers Fifth Fleet Admiral Raymond A. Spruance 36 escort carriers 11 battleships 26 cruisers 387 destroyers and destroyer escorts 394 AKA, AP, APA, APD, APH 977 LSD, LSM, LST, and LSV Seventh Fleet Admiral Thomas C. Kinkaid Air forces Far East Air Forces General George C. Kenney (119,000 men) – 14 bomber groups, 10 fighter groups Fifth Air Force Seventh Air Force Thirteenth Air Force United States Strategic Air Forces in the Pacific General Carl A. Spaatz Major General