Michael Moore's 1989 debut chronicling GM's gutting of Flint, Michigan. The film that taught Hollywood that documentaries could draw box office.
From Wikipedia
Roger & Me is a 1989 American documentary film written, produced, directed by, and starring Michael Moore, in his directorial debut. Moore portrays the regional economic impact of General Motors CEO Roger Smith's action of closing several auto plants in his hometown of Flint, Michigan, reducing GM's employees in that area from 80,000 in 1978 to about 50,000 in 1992.