Traditional histories of documentary films suggest a kind of natural evolution of the form as follows: When the Lumière brothers, who were among history's first cinematographers, started filming workers leaving their Lyon photography factory in the 1880s, they were making the first baby steps toward documenting the world as it existed around them. Then, in 1922, Robert Flaherty added narrative flair when he made the legendary "Nanook of the North" — and documentary film was born.
But in a closely argued essay, film theorist Bill Nichols argues that the documentary form really reached maturity in the 1920s because it was needed. This was an era when populations around the world were hard at work forging national identities. Documentaries, famously, give the impression that they're simply observing reality when, in fact, they're also shaping it. This quality made the medium an invaluable tool of state control by affirming certain cultural narratives and orthodoxies. By the same token, it made documentaries dangerous. If the medium could toe the party line and affirm a desirable reality, it could also disrupt it. That's why, Nichols argues, documentary film of the 1920s is closely aligned with our final subject: the modernist avant-garde [source: Nichols].