The Birth of a Nation (originally called The Clansman) is a 1915 American silent epic drama film directed and co-produced by D. W. Griffith and starring Lillian Gish. The screenplay is adapted from the novel and play The Clansman, both by Thomas Dixon Jr. Griffith co-wrote the screenplay (with Frank E. Woods), and co-produced the film (with Harry Aitken). It was released on February 8, 1915.

Three hours long, the film was originally presented in two parts separated by an intermission; it was the first 12-reel film in the United States. The film chronicles the relationship of two families in the American Civil War and Reconstruction era over the course of several years: the pro-Union Northern Stonemans and the pro-Confederacy Southern Camerons. The assassination of President Abraham Lincoln by John Wilkes Booth is dramatized.