One of the earliest American feature films (those with a story running in more than 6 reels of film, or about an hour in length) was David Wark Griffith's "The Birth of A Nation". This film, three times the length of any other major American film of its time, was a great technical and narrative achievement. It also sparked a firestorm, and did more than any other to show how the power of the new medium of film could be used to win more people over to a revisionist and one-sided view of history.
Griffith was a Kentuckian, born in 1875, and from his family was taught the "Lost Cause" view of the Civil War, that the cause of the Confederacy had little to do with slavery and more a matter of pure honor. He also learned that the Reconstruction Era (1865-77) had been a disaster for the South, instead of a lost opportunity to lead blacks and white Americans into the beginning of an integrated society.
Instead of focusing on the failures of the Federal Government in not fully supporting educational and economic opportunities for free men and women, Griffith saw the period as one that led to subservience by blacks over whites in a way that was a grotesque distortion of the real suffering and continued oppression of "Aryans", engendered by groups like the Klu Klux Klan. These terrorists were the heroes of the second half of his film.
This remarkable film was done by Charlotte Burger of Tufts University, New York. It is one of the best mini-documentaries I've found on the Internet lately.