The rebirth of the Klan began in 1915 when William J. Simmons, enamored of secret societies and fraternal organizations, attempted to resurrect the "Invisible Empire" at a ceremony in 1915 at Stone Mountain, Georgia, near Atlanta.He eventually managed to attract a small following in Alabama and Georgia. Simmons, born and raised in the South, was a Spanish-American War veteran, former Methodist preacher, freemason, and an organizer for the Woodmen of the World, a fraternal organization from which he received the honorary title, "colonel," for his recruiting efforts. He was also an alcoholic. Influenced by D.W. Griffith's racist depiction of the First Klan in Birth of a Nation, the messianic Simmons sought to revive a noble band of knights who would save white, Christian civilization. The Klansmen even wore the white robes and hoods as portrayed in the movie. The new Klan, however, remained just another small, secret fraternal organization.

Simmons expanded the Klan after the war by hiring a successful public relations firm from Atlanta, the Southern Publicity Association, operated by Edward Young Clarke and Mary Elizabeth Tyler. Clarke and Tyler transformed the second Klan into a business enterprise for a thirty percent cut of initiation fees. The firm hired kleagles (recruiters) on commission and began organizing klaverns (local chapters) throughout the deep South. Initiates paid ten dollars a head and swore the Klan oath. The millions of dollars flowing into the organization paid for Klan publications and activities, while exposing "Goblins," "Dragons," "Wizards," and other officials to temptation. Klaverns popped up across America in nearly every state. Indiana, Ohio, New York, and Illinois boasted the largest Klan organizations, and the KKK influenced local and state elections in Oklahoma, Oregon, Kansas, and Indiana. In 1921 the New York World published an exposé of the revived Klan, which prompted a Congressional hearing. After passionate testimony by Simmons, Congress failed to sanction the Klan and the press attention pushed Klan enrollment into the millions. The Klan also received the blessing of President Harding. By 1925, when Klan membership peaked, some historians estimate that enrollment reached 5 million.