Based on Thomas F. Dixon's novel and play, a southern family and a northern family interact during and after the Civil War as the Ku Klux Klan is born to win back power from the temporarily triumphant blacks.
In 1860 brothers Tod Stoneman (Robert Harron) and Phil Stoneman (Elmer Clifton) from Pennsylvania visit the Camerons in Piedmont, South Carolina. President Abraham Lincoln (Joseph Henabery) calls for 75,000 volunteers. The Stoneman brothers join the army, and three Camerons march off in gray uniforms.
Two and a half years later Col. Ben Cameron (Henry B. Walthall) gets a letter from his sister Flora Cameron (Mae Marsh). The first Negro militia is from South Carolina, and they join Union raiders attacking Piedmont; but the Confederates fight back to save the town. The youngest Cameron is killed. Elsie Stoneman (Lillian Gish) goes to nurse the wounded. Atlanta is burned, and another Cameron dies. General Lee orders an attack to rescue a food train. Ben Cameron leads the charge against Phil's men and is the only one to make it to the last line, where he is captured. Many are dead, and the North has won.
Mrs. Cameron (Josephine Crowell) mourns. Elsie nurses Ben Cameron and has a letter from Phil. Mrs. Cameron comes to visit Ben, who is to be hanged as a guerrilla. Mrs. Cameron appeals to President Lincoln, who pardons him. Ben sits up and talks with Elsie. Lee surrenders to General Grant. Ben says goodbye to Elsie and goes home, where Flora embraces him.
Austin Stoneman (Ralph Lewis) opposes Lincoln's clemency. He and Elsie attend the theater where Lincoln is cheered. John Wilkes Booth (Raoul Walsh) shoots Lincoln and jumps to the stage, shouting "Sic semper tyrannis!" Austin Stoneman tells the mulatto Silas Lynch (George Siegmann) that he is the equal of any, and he sends him south to organize Negro voters.
The Freedman's Bureau gives out free supplies. Ailing Austin Stoneman also goes south to Piedmont. Lynch meets Ben, who snubs him. Lynch speaks at a meeting. Ben courts Elsie, and she kisses him. Blacks vote while Confederates are disenfranchised. Lynch is elected lieutenant governor. Ben complains about black rule, and a faithful servant is punished. Blacks control the state legislature, and a bill allows interracial marriage.
Ben tells Gus (Walter Long) to move along, and Lynch complains. Ben sees children hide under a sheet. He forms the Ku Klux Klan to fight against blacks. Lynch and Austin Stoneman plan to crush them. Austin tells Elsie, who breaks her engagement to Ben. Flora tells Ben they have made 400,000 KKK costumes. Flora goes out for water. Gus tells her he wants to marry. She runs from him while Ben looks for her. Flora climbs up on a rock and jumps off. Ben finds her, and she dies. Gus hides in a gin mill. Whites search for Gus, and one fights blacks in the saloon. Gus shoots him and is caught fleeing. The KKK finds him guilty.
Lynch finds Gus's body on his steps and calls out the militia. The KKK orders blacks in the next county disarmed. Lynch has Dr. Cameron (Spottiswoode Aitken) arrested. The Camerons appeal to Elsie. Faithful servants help Dr. Cameron escape, but Elsie's brother killed a Negro. They find refuge in the cabin of two Union veterans. Elsie goes to Lynch, who asks her to marry. She refuses, but he plans to force her.
The KKK assembles and rides to the rescue. Austin arrives, and Lynch says he wants to marry his daughter. Blacks gather in town. The Union veterans fight for Dr. Cameron against blacks. The KKK attacks the blacks in town. Elsie and Austin are held captive until Ben and the Klan come in. Other clansmen rescue the besieged cabin. The blacks are disarmed, and the Klan parades. The KKK dominates the next election. They dream of peace with liberty and union.
This pioneering epic drama is powerful and biased propaganda
for white racism, reflecting the frustration of Euro-American
southerners for having lost their domination of African slave
labor in the Civil War. The humiliation of black rule during the
Reconstruction era led to the formation of the despicable Ku Klux
Klan that terrorized black people.