In 1941, the first Academy Award for best documentary went to the Canadian short Churchill's Island (1941), which chronicled Britain's defence against the Nazis. The following year, the documentary winners all reflected the United States' and its new military allies' escalating involvement in the propaganda war: John Ford's rousing color combat film The Battle of Midway, the Australian newsreel Kokoda Front Line!, the Soviet military orientation film Moscow Strikes Back and Frank Capra's Prelude to War. By 1945, all the documentary winners had been war films, and in 1946, after the war's end, there were no nominees for documentary feature (though the category reappeared the following year). Given these beginnings, arguably the best documentary Oscar – designed to celebrate works where ‘the emphasis is on fact’ (‘Rule Twelve’ 2010) – was based in one of motion pictures' key ideological functions: rallying popular opinion and patriotic sentiments during times of national crisis and war.

But the invention of the Academy's documentary category, some suggest, was about more than just endorsing film's role in the war effort. Patrick Stock-still, a coordinator for the awards, has seen it as part of a more widespread ‘recognition of the fact that documentary was becoming a bigger part of the theatrical experience’ (quoted in Mertes 1998: 7). The social functions of documentary in the US had coalesced during the 1930s and the form's stature continued to rise, significantly, after Pearl Harbor. Addressing and bridging demands for information, education and entertainment, the wartime documentary became a key mode for swaying public opinion and reinforcing ideas of citizenship, patriotism and national duty.