Information about the book that The Birth of a Nation was based off of.

The Clansman is a book published in 1905 and a play, part of a trilogy by Thomas F. Dixon, Jr. that also included The Leopard's Spots and The Traitor. It was influential in providing the mythology and ideology inherent in the rebirth of the Ku Klux Klan (KKK), after being filtered through a retelling in the movie The Birth of a Nation. The play made such an impact that many advocates for African American rights associated the film's racism with Dixon rather than director D.W. Griffith.
The play particularly inspired the second half of The Birth of a Nation, being concerned with the KKK and Reconstruction rather than the American Civil War. According to Professor Russell Merritt, key differences between the play and film are said to include the fact that Dixon was more sympathetic to Southerners pursuing education and modern professions, whereas Griffith stressed ownership of the plantation; moreover, Dixon envisioned the KKK as more professional and structured.
Dixon wrote The Clansman as a message to Northerners to maintain racial segregation, as the work claims that blacks when free turn savage.

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