During World War II the continental United States was in the enviable position of being separated from the front lines by two oceans, but this still did not make them immune from attacks on their home soil. Both the Japanese and the Germans had several plans for bombing the U.S. mainland.
Of course the attack on Pearl Harbor, Hawaii was what spurred the U.S. into World War II, but the Japanese had bigger plans for their bombers. Most of these centered around the brand new H8K, a four-engine seaplane with a 192 ft. wingspan. It had a range of 4,400 miles and could carry four tons of bombs at a top speed of 289 miles per hour. In 1942 the Japanese planned to have six H8K’s fly to the California coast, land on the water to be refueled by submarines, bomb Los Angeles, and then fly back to safe territory. If this mission was a success, the Japanese wanted to take thirty H8Ks and refuel them off of Baja California, where they would then fly to Texas and bomb the oil fields there. The planes would then fly onward to the Atlantic where they would meet up with German submarines stationed there and stage terror raids up and down the east coast of the U.S. The Germans were eager to cooperate and had prepared the tanker subs to refuel the H8Ks. All of these plans were scaled back after The Battle of Midway and never came to fruition.
The Japanese had another plan for attacking the mainland: hot air balloons. These unmanned balloons carried one 15-kilogram antipersonnel bomb and two incendiary devices. The Japanese hoped that these balloons could set fire to the vast forests of the Pacific Northwest, again this mission really only had terror and propaganda value. Between November 1944 and April 1945 the Japanese released more than 9,000 balloons. It is estimated that about 1,000 made it to North America, they have been found in Alaska and Mexico and as far east as Kansas. On May 5, 1945, five children and a woman were killed in Lakeview, Oregon when they found one of the balloons and tried to drag it out of the forest. These six people are the only known causalties of the balloon bombs, but many of the balloons have been found with their payloads still operational, so they may remain a threat to the unsuspecting hiker.
Meanwhile the Germans were working on their own long-range bomber. In 1942 the four-engine Me-264, or the “Amerika Bomber” first took flight. It could carry two tons of bombs 9,500 miles. It could fly from Europe to New York and back without having to land and could stay in the air for 45 hours. But problems on the Eastern Front caused them to delay their bombing plans until 1944. Early in the year, a six engine Ju-290, a light recon plane, made a flight over New York City and took photographs of likely targets. The British knew about the recon flight from decoded German messages, but chose not to tell the Americans until after it took place. Upon learning of the German plan the Americans sent swarms of bombers and destroyed the Me-264 plant. Not that it made much difference, by this late in the war the Luftwaffe was in no position to make such long flights and the Germans didn’t have enough resources to make enough planes anyway.