The Hump was the name given by Allied pilots in the Second World War to the eastern end of the Himalayan Mountains over which they flew military transport aircraft from India to China to resupply the Chinese war effort of Chiang Kai-shek and the units of the United States Army Air Forces (USAAF) based in China. Creating an airlift presented the USAAF a considerable challenge in 1942: it had no units trained or equipped for moving cargo, and there were no airfields in the China Burma India Theater (CBI) for basing the large number of transport aircraft that would be needed. Flying over the Himalayas was extremely dangerous and made more difficult by a lack of reliable charts, an absence of radio navigation aids, and a dearth of information about the weather.

The task was initially given to the USAAF's Tenth Air Force, and then to its Air Transport Command (ATC). Because the USAAF had no previous airlift experience as a basis for planning, it assigned commanders who had been key figures in founding the ATC in 1941–1942 to build and direct the operation, which included former civilians with extensive executive experience operating civil air carriers.

Originally referred to as the "India–China Ferry", the successive organizations responsible for carrying out the airlift were the Assam–Burma–China Command (April–July 1942) and the India-China Ferry Command (July–December 1942) of the Tenth Air Force; and the Air Transport Command's India-China Wing (December 1942 – June 1944) and India-China Division (July 1944 – November 1945).

The operation began in April 1942, after Japanese forces blocked the Burma Road, and continued daily until scaled down from August 1945. It procured most of its officers, men, and equipment from the USAAF, augmented by British, British-Indian Army, Commonwealth forces, Burmese labor gangs and an air transport section of the Chinese National Aviation Corporation (CNAC). Final operations were flown in November 1945 to return personnel from China.

The India–China airlift delivered approximately 650,000 tons of materiel to China at great cost in men and aircraft during its 42-month history. For its efforts and sacrifices, the India–China Wing of the ATC was awarded the Presidential Unit Citation on 29 January 1944 at the personal direction of President Franklin D. Roosevelt, the first such award made to a non-combat organization.

With the War of Resistance/World War II raging in China (1937–45), the Empire of Japan had effectively blockaded the entry of fuel and supplies into China by 1940, pushing the Republic of China government further hinterland to the new wartime capital of Chongqing, further culminating into the Japanese invasion of French Indochina and attack on Pearl Harbor, and necessitating the need in keeping the Chinese well-supplied for the continued fight against the Empire of Japan in the overall war effort. While committed to the success of the "Europe first" strategy of the Allied forces, keeping China well-supplied in the war on the Asian mainland would tie-down more than a million Japanese troops who might otherwise increase threat to the Allied strategic offensive in the Pacific War, had also become a priority. The Japanese invasion of French Indochina closed all sea and rail access routes for supplying China with war materiel except through central/north Asian states with the Soviet Union. That access ended following the signing of the Soviet–Japanese Neutrality Pact in April 1941 due to the need for the Soviets to commit to war against Nazi Germany, and the Burma Road became the only land route where supplies trickled in. The rapid success of Japanese military operations in Southeast Asia threatened this lifeline, prompting discussion of an air cargo service route from India; Chiang's foreign minister, T. V. Soong, estimated that 12,000 tons of materiel could be delivered monthly by air from India if 100 C-47 Skytrain-type transports were committed to an airlift. Chinese Air Force Major General Mao Bangchu was tasked with leading the exploration into suitable air-routes over the dangerous Himalayas in 1941, and commissioned CNAC pilot Charles L. Sharp flying for the first-time, this route which was to become known as The Hump in November of that year.

On 25 February 1942, President Roosevelt wrote to General George C. Marshall that "it is of the utmost urgency that the pathway to China be kept open", and committed ten C-53 Skytrooper transports for lend-lease delivery to CNAC to build its capability to 25 aircraft. When the newly created Tenth Air Force opened its headquarters in New Delhi under the command of Maj. Gen. Lewis H. Brereton in March 1942, it was assigned the responsibility of developing an "India-China Ferry" using both U.S. and Chinese aircraft. Although he was never given command authority over aircraft or personnel, the officer responsible for the India-China Ferry was Brereton's chief of staff Brig. Gen. Earl L. Naiden, who held that responsibility until mid-August.

From its onset, the air route was predicated on operating two branches, unofficially deemed "commands": a "Trans-India Command" from India's western ports to Calcutta, where cargo would be transshipped by rail to Assam; and the "Assam-Burma-China Command", a route from bases in Assam to southern China. The original scheme envisioned the Allies holding northern Burma and using Myitkyina as an offloading terminal to send supplies by barge downriver to Bhamo and transfer to the Burma Road. However, on 8 May 1942 the Japanese seized Myitkyina which, coupled with the loss of Rangoon, effectively cut Allied access to the Burma Road. To maintain the uninterrupted supply to China, U.S. and other allied leaders agreed to organize a continual aerial resupply effort directly between Assam and Kunming.