<P> The invasion of Normandy, France, was the largest and most complex amphibious operation of all time . Casualties were remarkably small, with the Germans having hardly any airpower or seapower to combat it . In the first 30 days, the armada landed 850,000 men, 148,000 vehicles, and 570,000 tons of supplies on the beaches and makeshift ports, for the Germans were holed up in control of all the regular ports . The operation involved 195,000 men from the various navies and merchant marine . The navies used 113,000 British, 53,000 American, and 5000 men from other allies . In addition there were 25,000 sailors from the Allied merchant navies . Of the combat warships, 17 percent were provided by the United States Navy, and 79 percent by the British or Canadians . Since the preponderance of naval forces were British, the Royal Navy named Vice Admiral Bertram Ramsay as the overall neighbor naval commander under Eisenhower . </P> <P> Okinawa was the last great battle of the entire war . The goal was to make the island into a staging area for the invasion of Japan scheduled for fall 1945 . It was just 350 miles (550 km) south of the Japanese home islands . Marines and soldiers landed on 1 April 1945, to begin an 82 - day campaign which became the largest land - sea - air battle in history and was noted for the ferocity of the fighting and the high civilian casualties with over 150,000 Okinawans losing their lives . Japanese kamikaze pilots enacted the largest loss of ships in U.S. naval history with the sinking of 38 and the damaging of another 368 . Total U.S. casualties were over 12,500 dead and 38,000 wounded, while the Japanese lost over 110,000 men . The fierce combat and high American losses led the Navy to oppose an invasion of the main islands . The eventual bombings of Hiroshima and Nagasaki, along with the Soviet invasion of Manchukuo led to the Japanese surrender in August 1945 . </P> <P> Technology and industrial power proved decisive . Japan failed to exploit its early successes before the immense potential power of the Allies could be brought to bear . In 1941, the Japanese Zero fighter had a longer range and better performance than rival American warplanes, and the pilots had more experience in the air . But Japan never improved the Zero and by 1944 the Allied navies were far ahead of Japan in both quantity and quality, and ahead of Germany in quantity and in putting advanced technology to practical use . High tech innovations arrived with dizzying rapidity . Entirely new weapons systems were invented--like the landing ships, such as the 3,000 ton LST ("Landing Ship Tank") that carried 25 tanks thousands of miles and landed them right on the assault beaches . Furthermore, older weapons systems were constantly upgraded and improved . Obsolescent airplanes, for example, received more powerful engines and more sensitive radar sets . One impediment to progress was that admirals who had grown up with great battleships and fast cruisers had a hard time adjusting their war - fighting doctrines to incorporate the capability and flexibility of the rapidly evolving new weapons systems . </P> <P> The ships of the American and Japanese forces were closely matched at the beginning of the war . By 1943 the American qualitative edge was winning battles; by 1944 the American quantitative advantage made the Japanese position hopeless . The Kriegsmarine, distrusting its Japanese ally, ignored Hitler's orders to cooperate and failed to share its expertise in radar and radio . Thus the Imperial Navy was further handicapped in the technological race with the Allies (who did cooperate with each other). The United States economic base was ten times larger than Japan's, and its technological capabilities also significantly greater, and it mobilized engineering skills much more effectively than Japan, so that technological advances came faster and were applied more effectively to weapons . Above all, American admirals adjusted their doctrines of naval warfare to exploit the advantages . The quality and performance of the warships of Japan were initially comparable to that of the US . </P>

How many aircraft carriers did the us have at the end of ww2