Even if the African American people won the
battle against the “black codes” in the Southern States helped by the
Republican Party, now they were faced to a new problem… the Ku Klux Klan (KKK).

Founded in 1866, the Ku Klux Klan extended into
almost every southern state by 1870 and became a vehicle for white southern
resistance to the Republican Party’s Reconstruction. Its members, a group formed
by many Confederate veterans, acted as a campaign of intimidation and violence against
white and black Republican leaders. Its leader was Nathan Bedford Forrest a
Confederate general, the first leader, called the “Grand Wizard” of the Klan; he
presided over a hierarchy of grand dragons, grand titans and grand cyclopses. They
were joined by similar organizations such as the Knights of the White Camelia (from
Louisiana) and the White Brotherhood. When the Congress passed a legislation in
order to curb Klan terrorism, the organization saw its primary goal, to re-establish
the white supremacy. Little by little, black legislators elected during the
1867-1868 constitutional conventions became victims of violence during
Reconstruction, even seven of them were killed. Quickly, black institutions
such as schools and churches, symbols of black autonomy, were also targets for
Klan attacks.
Their attacks were mainly at night, acting on
their own but in support of the common goals of defeating Radical
Reconstruction and restoring white supremacy in the South. Klan activity
flourished particularly in where blacks were a minority. Among the most
notorious zones of Klan activity was South Carolina, where in January 1871, 500
masked men attacked the Union county jail and lynched eight black prisoners.
As everybody feared the terrorist group (nobody
wanted to testify against them), the Republican state governments in the South
turned to Congress for help, resulting in the passage of three Enforcement
Acts, the strongest of which was the Ku Klux Klan Act of 1871
.
For the first time, the act authorized the
president to suspend the writ of habeas corpus (summons with the force of a
court order) and arrest accused individuals without charge, and to send federal
forces to suppress Klan violence. This expansion of federal authority alarmed
many Republicans and by the end of 1876, the entire South was under Democratic
control once again.
In 1915, reappeared the Ku Klux Klan near
Atlanta, Georgia, formed by white Protestant nativists. However, this second
generation of the Klan was not only anti-black but also against Roman
Catholics, Jews, foreigners and organized labour. The organization took as its
symbol a burning cross and held rallies, parades and marches around the country.
By 1920, Klan membership exceeded 4 million people nationwide.
The cases of Klan in relation to violence
became more isolated in the decades to come. However, the group was fragmented and
became aligned with neo-Nazi or other right-wing extremist organizations from
the 1970. In the early 1990s, the Klan was estimated to have between 6,000 and
10,000 active members, mostly in the Deep South.
Source: http://www.history.com/topics/ku-klux-klan