Which organization in Indiana was noted for having the largest membership outside of the Southern states in 1922?

The correct choice reflects a significant historical reality about the Ku Klux Klan in the early 20th century. In the 1920s, the Klan experienced a resurgence not only in the South but also in northern states, including Indiana, where it became very influential. The Klan's membership grew substantially, particularly in Indiana, where it gained notable political clout. By 1922, it was reported that Indiana had one of the largest concentrations of Klan members outside of the Southern states, highlighting its prominence and impact on local politics and society during that time.

The other organizations mentioned, while significant in their own contexts, did not match the Klan's membership levels in Indiana during the specified period. The American Legion is a patriotic veterans' organization that focuses on supporting veterans and military families, while The Elks is a fraternal order that promotes charitable work and community service. The NAACP, an organization dedicated to civil rights and fighting racial injustice, was still in its formative years at this time and did not have the same level of membership or influence in Indiana as the Klan. Understanding this context is crucial for grasping the dynamics of membership and social movements in the U.S. during the early 20th century.