Final answer:
The revival of the Ku Klux Klan in the 1920s was driven by nativism, protests against racial discrimination, and fears of social changes, drawing in 4 million members at its peak. Despite claims of nonviolent intent, its members engaged in intimidation and violence. The Klan's decline began in the mid-1920s due to public condemnation and internal corruption.
Step-by-step explanation:
An increase in protests against segregation and racial discrimination after World War I, along with rapid social changes and the growth of a nonwhite and non-Protestant population, contributed to the resurgence of the Ku Klux Klan during the 1920s. The reinvented Klan appealed to middle-class Americans' fears and prejudices, providing a sense of identity and belonging through its social gatherings and nationalistic rituals. Despite its claim to nonviolence, the Klan continued to practice intimidation and violence, and its influence spread widely, with membership peaking at 4 million in 1925.
The Klan's growth was also supported by the popularity of the film Birth of a Nation and the eugenics movement, which stoked fears of other races and immigrants. At the same time, the 1920s saw a strong civil rights response with increased efforts by organizations like the NAACP to combat the Klan's ideology and violence. Despite this activism, the Klan's impact on American society was substantial and reflective of broader sentiments of the era.
However, by the mid-1920s, the Klan's membership began to decline due to public denunciation from conservatives and liberals alike, revelations of financial misdeeds within the organization, and a lack of enduring enthusiasm for their negative message.