It adopted the Dunning School's historical outlook and was based on a Thomas Dixon play about the Thaddeus P. Stevens spoof, Austin Stoneman.  
It was based on the second part of a trilogy of plays, the last of which was The Traitor.  Duke, Wade and Benjamin make up the three sons of one of this work's families, and its innovations included using magnesium flares to capture night shots.  The mulatto Lydia Brown causes the disastrous sexual attraction of a prominent senator in one scene, while later Gus forces Flora to jump off a cliff after she rejects his marriage proposal.  It adopted the Dunning School's historical outlook and was based on a Thomas Dixon play about the Thaddeus P. Stevens spoof, Austin Stoneman.  For 10 points, identify this landmark 1915 D. W. Griffith silent film notorious for its idealized portrayal of the Ku Klux Klan.
It was based on the second part of a trilogy of plays, the last of which was The Traitor.  
The {Birth of a Nation} (or The {Clansmen})