With the passage of the Civil Rights Act of 1964 prohibiting racial discrimination in employment, public access and housing, Negroes took a more aggressive public stand for voting rights and economic opportunity. Demonstrations, pickets and boycotts were designed by civil rights organizers to break the stronghold of "massive resistance" led by the white Citizen's Councils.   The Ku Klux Klan had been fairly inactive in Mississippi since the 1930's, but challenges to white supremacy brought a resurgence. 5000 anxious and angry whites reorganized as The White Knights of the KKK. The mission of the Klan, led by Imperial Wizard Sam Bowers, was the total destruction of the Mississippi civil rights movement. Its constitution denounced Negroes, Jews and Catholics as well as those advocating moderate positions. The F.B.I. attributed nine murders and 300 beatings, burnings and bombings to the White Knights.