Only 47 of these aircraft dropped bombs near the raid's primary target, the Imperial Iron and Steel Works at Yawata in northern Kyūshū, and little damage was caused.

While the raid did not achieve its aims, it raised Japanese civilians' awareness that their country was being defeated and received positive media coverage in the United States.

The Japanese government responded to the attack by both increasing the number of fighter units based in the home islands and conducting an offensive in the Pacific Ocean which ended in defeat during the Battle of Midway.

The Superfortress was the largest combat aircraft of World War II and boasted a heavy maximum bomb load, long range, and powerful defensive armament.

While 1,664 B-29s had been ordered by the USAAF before the aircraft first flew, its development was set back by several months when the second prototype crashed on 18 February 1943[b] and problems with the design were gradually solved.

[6] In late 1943, the United States Joint Chiefs of Staff approved a proposal to begin a strategic air campaign against the Japanese home islands and East Asia by basing B-29s in India and establishing forward airfields in areas of China.

This strategy, which was designated Operation Matterhorn, required the construction of large airstrips near Chengdu in inland China which would be supplied by Allied cargo aircraft and be used to refuel B-29s traveling from bases in Bengal en route to bombing targets in Japan.

[7] XX Bomber Command was assigned responsibility for this effort, and its ground crew began to leave the United States for India by sea in December 1943.

[10] The 58th Bombardment Wing was XX Bomber Command's main combat unit, and its movement from Kansas to India took place from April to mid-May.

[11] While the wing had not completed training at the time that it left for India, its combat groups were more experienced than most newly deployed USAAF bomber units.

[15] Moreover, continued technical problems with the Superfortress, and particularly their Wright R-3350 engines, resulted in many of XX Bomber Command's aircraft being unserviceable and in need of modification at all times.

[17] On 6 June, Wolfe received a message from Arnold informing him that the Joint Chiefs of Staff wanted a raid to be conducted against Japan as soon as possible.

[18] The target selected for the first raid on Japan was the Imperial Iron and Steel Works at Yawata, an industrial city about 1,600 miles (2,600 km) from Chengdu.

[23] Japanese intelligence services deduced that once logistical preparations were complete, the heavy bombers would attack factories in northern Kyūshū, and that the first raid would be made at night.

[24] The Japanese military began transferring fighter aircraft from China and the Pacific to the home islands in early 1944 in anticipation of B-29 raids.

The 4th Air Regiment was stationed at Ozuki Airfield and was equipped with 35 Kawasaki Ki-45 Toryu twin-engined heavy fighters, of which 25 were operational in mid-June, and had the brigade's best-trained pilots.

While this inflexible deployment was considered unsatisfactory by the 19th Air Brigade, it was deemed necessary, as few aircraft were available, the only searchlight units needed to facilitate night operations were stationed near Yawata and northern Kyūshū was regarded by the Army as being the most important region in the Western District.

[31] Prior to the raid on Yawata, the 19th Air Brigade undertook joint planning with anti-aircraft units and implemented a training program which included practice in responding to alerts and night flying.

A large number of staff officers, including eight generals, also traveled to Chengdu to observe the operation but were not allowed to participate in the raid.

[39][40] After the first bombs were released, regular updates on the operation were transmitted to the Twentieth Air Force's headquarters in Washington, from where they were relayed to Arnold, who was in London at the time.

These photos showed that only a single bomb had landed within the Imperial Iron and Steel Works complex, and it had hit a powerhouse 3,700 feet (1,100 m) from the nearest coke oven.

[46] The light combat losses suffered by the raiders and electronic intelligence collected by the B-29s revealed the ineffectiveness of Japanese radar and air defenses.

[41] In response to the raid, Japanese Government ministers urged families living in the country's four major cities to evacuate their children to rural areas.

[52] XX Bomber Command conducted 49 raids from its bases in China and India between June 1944 and March 1945, of which nine were made on targets in the Japanese home islands, but Operation Matterhorn did not achieve its goals.