|Internet download of Klan march in Washington, DC, either 1925 or 1926.|
Note display of American flags, which was standard for the Klan in that era.
A third era Klan arose in the 1960s as very loosely connected chapters, primarily in the southern states, symbolized by association with the Confederate flag, in opposition to civil rights and voting rights for African-Americans. The Klan exists presently as white supremacy organizations in many states but without any semblance of national coordination, estimated at 10,000 individuals.
RESEARCH ON THE SECOND ERA KU KLUX KLAN
Kathleen M Blee authored a book: Women of the Klan. An excerpt is posted at http://xroads.virginia.edu/~ug97/blues/klan3.html.