The 'Best Documentary Feature' category was not part of the original Oscars. It was introduced during WWII as a way to recognize the vital role of non-fiction filmmaking in the war effort. The first winner was the 1942 film 'Churchill's Island' (in a short category), but the first feature-length winner was 'The Secret Land' in 1948. However, 1942 is considered the turning point for the category when the Academy gave a special award to 'Kukan,' a film about the resistance in China. The category has since evolved from a propaganda tool into a highly competitive field for investigative journalism and artistic non-fiction. Documentary winners like 'O.J.: Made in America' (which is nearly 8 hours long) have pushed the boundaries of what constitutes a 'motion picture,' leading the Academy to create new rules regarding multi-part series.