The final 20 minutes of Kukan show a Japanese air raid on the defenseless city on Aug 19 and 20, 1940, and many critics have hailed the segment as the most impressive part of the documentary. Scott recorded the lives of the local people during the two-day barrage, showing how they tried to hide from the bombardment. He also captured footage of the bombed-out downtown from the roof of the US embassy on the other side of the Yangtze River.

Reviewing Kukan in The New York Times on its release, movie critic Bosley Crowther described the closing sequence as "one of the most awesome bits of motion picture yet seen in this day of frightful news events ... somehow this wanton violence appears even more horrible than the scenes we have witnessed of London's destruction".

The Academy Award came in the form of a certificate, rather than a statue. Scott was commended "for his extraordinary achievement in producing Kukan, the film record of China's struggle, including photography with a 16-mm camera under the most difficult and dangerous conditions". Although she was co-producer and sponsor, Li was listed as "technical advisor" in the film's credits.

'An epic film'

Zhou, who is also professor of modern Chinese history at the Southwest University in Chongqing, called Kukan "an epic film" about China's resistance to the Japanese occupation, and said it provides new evidence of Japan's aerial bombing campaign and the unprovoked killing of civilians.

"It is the only award-winning film that tells the story of China's fight against Japan's invasion," he said.

"At the time, the film alerted the US government and its people to Japan's wartime atrocities, the Chinese people's huge sacrifice and the country's important role during the war. In the end, the two countries became allies to fight Japan."

According to Lung, when Kukan premiered in June 1941, Washington was still maintaining a policy of neutrality, but the film clearly depicted the brutality of the Japanese military machine and became a rallying point for those eager to sway public opinion toward US engagement in WWII.

Henry Luce, a US publishing magnate who owned Time, held a private screening for his employees, and the film was also used as a fund-raising tool by a number of relief organizations. However, despite the movie playing in theaters across the US, it was never screened in China.

After the war, few Western historians focused on China's eight-year battle, and the country's resistance was marginalized in histories of the global conflict, according to Zhou.

"The film will help historians to recognize China's role in the war, and help China and the United States to cherish their common past and share the responsibility of safeguarding the post-war world order," he added.

In 2013, Rana Mitter, professor of modern Chinese history and politics at the University of Oxford in England, published China's War With Japan, 1937-1945: The Struggle for Survival, in which he argued that China's crucial role in WWII has been airbrushed from history. The US edition of the book is called Forgotten Ally.

Mitter, who viewed Kukan during a visit to Chongqing, said he hadn't heard of the movie until his trip, but he was deeply impressed by the detailed record of life during wartime.

"I didn't previously know about Kukan. However, it's a goldmine-a really valuable perspective on China's wartime capital," the British historian said. "The fact that it's in color gives real immediacy to the war. It's horrifying to see the bombing raids over Chongqing, but it's very heartening to see the scenes of children in school and people trading in the streets, carrying on with their lives despite the terrible circumstances of the conflict."

Li Danke, professor of history at Fairfield University in the US, described Kukan as "an encyclopedia" of the wartime history of Chongqing, China's many ethnic groups and the Chinese diaspora.

"Overseas Chinese, such as Li Ling-Ai, made great contributions to China and America during the war. The rediscovery of Kukan will help to enhance the status and influence of Chinese-Americans in American society," she said.

Contact the writer at [email protected]

From left: A poster of Kukan, which was awarded an honorary Oscar by the US Academy of Motion Picture Arts and Science in 1942. Two posters for Robin Lung's documentary Finding Kukan, in which Li Ling-Ai and Rey Scott are pictured.