Final answer:
The term "documentary film" was coined in 1926 by John Grierson, and the genre has since become a significant form of art used for education, social commentary, and historical storytelling, with pioneers such as Robert Flaherty and Ken Burns shaping its trajectory.
Step-by-step explanation:
In 1926, the term "documentary film" was coined by John Grierson, a pioneering Scottish filmmaker, critic, and educator. Grierson's principles of documentary were that cinema's potential for observing life could be exploited in a new art form; his definition of documentary as 'creative treatment of actuality' has gained wide acceptance. The use of film for ethnographic and anthropological endeavors, as well as the work of filmmakers like Robert Flaherty, whose film Nanook of the North is often considered a precursor to the documentary genre, show the natural progression toward Grierson's formalization of the term. Additionally, the evolution of ethnographic film and the work of figures like Ken Burns highlight the development and importance of documentary film in capturing and interpreting the human experience.
The documentary film has been an important tool for teaching, storytelling, and social commentary. It was further developed by explorers like Robert Flaherty and became an established genre under Grierson's influence. The use of documentary techniques has expanded over time, including the adoption of synchronized sound technologies in the 1960s, which allowed for the subjects' voices to be heard, and a more critical look at the dynamics involved in the representation of cultures by Western filmmakers. Ken Burns is one such documentarian who has greatly enriched the narrative of American history through his extensive works, applying the documentary approach to historical storytelling.