The inspired, driven, and technically advanced film, Birth of a Nation (1915), also is a study in unvarnished racism at the beginning of the 20th century. Southerner and director D.W. Griffith's three-hour work was inspired by his personal background. He was the son of a Confederate cavalry officer who came home seared by war to face Reconstruction — the veteran blamed the latter and southern blacks' rise to power for his disgraced denouement. The film's simple plot is based on The Clansman, written by Thomas Dixon. Two friendly families end up on opposite sides in the Civil War. The Stonemans, whose patriarch is politician Austin Stoneman, live in the north, while the Camerons, headed by "Little Colonel" Ben Cameron, reside in the south. The war inflicts a disastrous impact on each family. Reconstruction dominates the storyline from then on. Stoneman, who has become a carpetbagger, moves south with his kin, then becomes obsessed with his mulatto housekeeper. In addition, he engineers the political rise of Silas Lynch, another mulatto. Meanwhile, Cameron looks on as blacks assume control of the state legislature, bedevil his daughter and other whites. "Little Colonel" seeks revenge by instituting the Ku Klux Klan to struggle against those who would obliterate his world. President Woodrow Wilson, at one point a Princeton professor of political science, watched the film in the White House. Likely reflecting his Southern background, he pronounced it historically accurate — "history writ with lightning." Numerous whites concluded it was an authentic reflection of race and politics at the time. Further, the ranks of a rejuvenated Ku Klux Klan began to swell. The film's release aroused the chagrin and ire of the National Association for the Advancement of Colored People and other groups. Whether it should be shown in New York was the subject of an acrid debate among the National Board of Censorship of Motion Pictures; this was provoked by W.E.B. DuBois' caustic comments in the NAACP magazine, The Crisis. Many historians attribute severe nationwide race riots of the period to the film's inflammatory core.